Use of highly branched polymers in polymer dispersions for gloss colours

ABSTRACT

The present invention relates to a method of producing coatings with increased gloss, to aqueous coating materials for such a method, and to the use of highly branched polymers as an additive for aqueous polymer dispersions for coating materials that lead to coatings having increased gloss.

The present invention relates to a method of producing coatings withincreased gloss, to aqueous coating materials for such a method, and tothe use of highly branched polymers as an additive for aqueous polymerdispersions for coating materials that lead to coatings having increasedgloss.

Paints are typically divided into three categories according to theircapacity to reflect light:

-   1. flat paints, with a specular gloss of less than 15% reflectance;-   2. semigloss paints, with a specular gloss of about 35% to 50%    reflectance; and-   3. high-gloss paints, with a specular gloss of >70% reflectance;    based in each case on light with an angle of incidence of 60°.

The quality of unpigmented and especially pigmented coating materialsbased on aqueous polymer dispersions depends critically on the gloss ofthe resultant coatings. Consequently there has been no lack of attemptsto improve the gloss by means of suitable additions. In many cases,however, these additions have the disadvantage of still exhibiting acertain volatility, which impacts negatively on the VOC of the resultantcoatings.

WO 00/29495 describes a coating material which comprises a solvent, analkyd resin (polyester resin), and a star polymer. The star polymers insuch materials serve as modifiers for improving the performanceproperties of the coating materials, such as for achieving a lowerviscosity, for example. They derive from polyfunctional thiols whichcontain at least three vinylically unsaturated side chains.

WO 01/96411 describes amphiphilic star polymers which have amercaptan-based core from which there proceed at least three polymerarms, and also describes the use of these star polymers to stabilizeaqueous polymer dispersions.

WO 2004/016700 describes a water-based copolymer dispersion which isobtainable by copolymerization using at least one dendritic polymerwhich is functionalized with alkylene groups. The resulting copolymerdispersions are notable for improved blocking properties. The documentdoes not teach the addition of a highly branched polymer to an aqueouspolymer dispersion for the purpose thereby of providing aqueous coatingmaterials that lead to coatings with increased gloss.

WO 2004/016701 describes an aqueous homopolymer or copolymer dispersion,obtainable by means of emulsion polymerization, where analkenyl-functionalized dendrimer is used as an addition. The compositionmay be used as a binder for coatings. Its use for increasing the glossis not disclosed.

WO 2004/037928 describes an air-drying aqueous resin compositioncomposed of a fatty acid-functionalized hyperbranched polymer whichdries in the air, a nonamphiphilic alkyd resin, a dryer, and astabilizer.

WO 2005/003186 describes a process for preparing aqueous polymerdispersions based on copolymers which incorporate at least onehydrophobic allyl, vinyl, maleic or diene monomer, the polymerizationtaking place in the presence of at least one dendritic polymer. Thedendritic polymer in this system enables the use even of stronglyhydrophobic monomers having a water solubility of less than 0.001 g/lfor the emulsion polymerization. The use of such dendritic polymers asan addition to polymer dispersions for the purpose thereby of providingaqueous coating materials that lead to coatings with increased gloss isnot described.

EP 1006165 A2 describes a coating composition comprising a vinyl polymerwith appended carbosiloxane dendrimer groups. These groups areintroduced by free-radical copolymerization with vinyl-functionalizedcarbosiloxane dendrimers. The coating composition serves for theconstruction industry, buildings, automobiles, etc. The coating isresistant to weather, water, and icing, and exhibits good glossmaintenance and water repulsion.

K. Manczyk, P. Szewczyk describe, in Prog. Org. Coat. 2002, 44, 99-109,highly branched high-solids alkyd resins. These resins may be based bothon star-shaped structures and on hyperbranched structures. As the degreeof branching went up, the drying of these alkyd resins became quicker.Besides other performance properties, the gloss is reported as well. Thedocument, however, does not reveal the suitability of hyperbranchedpolymers as a specific addition for gloss improvement. A comparabledisclosure content is that of the article by E. Bat, G. Gündüz, D.Kisakürek, and I. M. Akhmedoc in Prog. Org. Coat. 2006, 55, 330-336.

It was an object of the present invention to provide aqueous polymerdispersions for use in paints with increased gloss. The dispersionsought especially to serve to increase the gloss of gloss paints based onacrylate dispersions.

Surprisingly it has been found that this object is achieved through theuse of highly branched polymers in aqueous polymer dispersions forcoating materials.

The invention first provides, therefore, a method of producing a coatingwith increased gloss by applying to a substrate an aqueous coatingmaterial which comprises an aqueous polymer dispersion PD) and a highlybranched polymer.

The invention further provides coating materials in the form of anaqueous composition comprising:

-   -   at least one dispersion as defined below which comprises a        highly branched polymer as an additive,    -   if appropriate, at least one inorganic filler and/or inorganic        pigment,    -   typical auxiliaries, and    -   water to 100% by weight.

The invention further provides a method increasing the gloss of acoating based on an aqueous polymer dispersion PD), which is obtainableby free-radical emulsion polymerization of at least oneα,β-ethylenically unsaturated monomer M), by addition of at least onehighly branched polymer.

The addition of the highly branched polymers to the polymer dispersionPD) may be made before and/or during and/or after the emulsionpolymerization for the preparation of PD). Addition after the emulsionpolymerization also comprises addition as part of the formulation of aproduct that comprises an emulsion polymer based on at least oneα,β-ethylenically unsaturated monomer M). For that purpose at least onehighly branched polymer as defined below may be added as an additive toa paint. The invention further provides, therefore, for the use of atleast one highly branched polymer as an additive for a product thatcomprises an emulsion polymer based on at least one α,β-ethylenicallyunsaturated monomer M), as defined below, to increase the gloss of thecoatings produced therefrom.

The invention further provides for the use of highly branched polymersas defined below as an additive for aqueous coating materials whichcomprise an aqueous emulsion polymer PD) for increasing the gloss of thecoatings produced therefrom.

The invention further provides for the use of an aqueous polymerdispersion PD) which comprises a highly branched polymer as an additiveas a component in transparent varnishes and in high-gloss paints.

The gloss of the paint can be determined by DIN 67530. The paint isapplied with a slot width of 240 μm to a glass plate and is dried atroom temperature for 72 hours. The test specimen is inserted into acalibrated reflectometer, and, with a defined incident angle, a recordis made of the extent to which the light returned has been reflected orscattered. The reflectometer value determined is a measure of the gloss(the higher the value, the higher the gloss).

The gloss of semigloss paints is preferably greater than 15 at 60°. Thegloss of high-gloss paints based on the coating materials of theinvention is preferably greater than 60 at 20°. The gloss of high-glosspaints is preferably greater than 80 at 60°.

The polymer dispersion PD) used in accordance with the inventioncomprises preferably 0.1 to 15% by weight, more preferably 0.5% to 10%by weight, based on the total weight of the polymer dispersion, of atleast one highly branched polymer. Typical amounts of the highlybranched polymer are situated, for example, within a range from 1% to 5%by weight.

The inventive use of the highly branched polymers is accompanied by atleast one of the following advantages:

-   -   increase in the gloss of coating materials (paints), especially        of gloss paints based on acrylate dispersions,    -   high compatibility of the highly branched polymers employed with        a multiplicity of dispersions,    -   at least partial avoidance of additives that increase the VOC        content of the dispersions.

Added in accordance with the invention to the polymer dispersion PD) isat least one highly branched polymer. The expression “highly branchedpolymers” refers for the purposes of this invention, quite generally, topolymers which are distinguished by a strongly branched structure and ahigh functionality. For the general definition of highly branchedpolymers, reference is also made to P. J. Flory, J. Am. Chem. Soc. 1952,74, 2718, and H. Frey et al., Chem. Eur. J. 2000, 6, No. 14, 2499 (wherethey are referred to, in deviation from the definition chosen here as“hyperbranched polymers”).

The highly branched polymers in the sense of the invention include starpolymers, dendrimers, arborols, and different highly branched polymers,such as, specifically, hyperbranched polymers.

Star polymers are polymers in which three or more chains extend from acenter. This center may be a single atom or a group of atoms.

Dendrimers derive structurally from the star polymers, but with starbranching in each of the individual chains. Dendrimers are formedstarting from small molecules by means of a continually repeatingreaction sequence resulting in ever higher numbers of branches, at whoseends there are in each case functional groups which, in turn, are astarting point for further branches. Hence the number of monomer endgroups grows exponentially with each reaction step, ultimately resultingin a tree structure which in the ideal case is spherical. Acharacteristic feature of the dendrimers is the number of reactionstages (generations) carried out for the purpose of their synthesis. Onthe basis of their uniform construction (in the ideal case, all of thebranches comprise exactly the same number of monomer units), dendrimersare substantially monodisperse, i.e., they generally have a definedmolar mass.

Both molecularly and structurally uniform highly branched polymers willalso be referred to in common below as dendrimers.

“Hyperbranched polymers” in the context of this invention are highlybranched polymers which, in contradistinction to the abovementioneddendrimers, are both molecularly and structurally nonuniform. They haveside chains and/or side branches which differ in length and branchingand also in their molar mass distribution (polydispersity).

The highly branched polymers in accordance with the invention preferablyhave a degree of branching (DB) per molecule of 10% to 100%, morepreferably 10% to 90%, and more particularly 10% to 80%. The degree ofbranching, DB is defined by DB(%)=(T+Z)/(T+Z+L)×100, where

-   T is the average number of terminally attached monomer units,-   Z is the average number of branch-forming monomer units,-   L is the average number of linearly attached monomer units.

Dendrimers generally have a degree of branching DB of at least 99%,especially 99.9% to 100%.

Hyperbranched polymers preferably have a degree of branching DB of 10%to 95%, more preferably 25% to 90%, and more particularly 30% to 80%.

In order to achieve advantageous gloss properties it is possible to usenot only structurally and molecularly uniform dendrimers but alsohyperbranched polymers. Hyperbranched polymers, however, are generallyeasier and hence more economic to prepare than dendrimers. Thus, forexample, the preparation of the monodisperse dendrimers is complicatedby the fact that, at each linking step, protective groups are introducedand have to be removed again, and, before the beginning of each newgrowth stage, intense cleaning operations are needed, which is whydendrimers can typically be prepared only on a laboratory scale.Hyperbranched polymers, with their molecular weight distribution, canalso have an advantageous effect on the viscosity properties of thedispersions that are modified with them. Hyperbranched polymers,moreover, have a more flexible structure than the dendrimers.

Suitability as highly branched polymers is possessed in principle bythose which are obtainable by polycondensation, by polyaddition or byaddition polymerization of ethylenically unsaturated compounds.Preference is given to polycondensates. By polycondensation is meant therepeated chemical reaction of functional compounds with suitablereactive compounds, with elimination of compounds of low molecular mass,such as water, alcohol, HCl, etc. By polyaddition is meant the repeatedchemical reaction of functional compounds with suitable reactivecompounds, without elimination of compounds of low molecular mass.

Suitability is possessed by polymers which contain functional groupsselected preferably from ether groups, ester groups, carbonate groups,amino groups, amide groups, urethane groups, and urea groups.

As polymers it is possible more particularly to use polycarbonates,polyesters, polyethers, polyurethanes, polyureas, polyamines, andpolyamides, and also their hybrid forms, such as, for example,poly(ureaurethanes), poly(etheramines), poly(esteramines),poly(etheramides), poly(esteramides), poly(amidoamines),poly(estercarbonates), poly(ethercarbonates), poly(etheresters),poly(etherestercarbonates), etc.

Preferred hyperbranched polymers are those based on ethers, amines,esters, carbonates, amides, and also their hybrid forms, such as, forexample, esteramides, amidoamines, estercarbonates, ethercarbonates,etheresters, etherestercarbonates, ureaurethanes, etc.

As hyperbranched polymers it is possible more particularly to usehyperbranched polycarbonates, hyperbranched poly(ethercarbonates),hyperbranched poly(etheresters), hyperbranchedpoly(etherestercarbonates), hyperbranched polyester, hyperbranchedpolyethers, hyperbranched polyurethanes, hyperbranchedpoly(ureaurethanes), hyperbranched polyureas, hyperbranched polyamines,hyperbranched polyamides, hyperbranched poly(etheramine)s, hyperbranchedpoly(esteramine)s, hyperbranched poly(etheramide)s, hyperbranchedpoly(esteramide)s, and mixtures thereof. Once specific version ofhyperbranched polymers are hyperbranched polycarbonates. Anotherspecific version of hyperbranched polymers are hyperbranched polymerscontaining nitrogen atoms, especially polyurethanes, polyureas,polyamines, polyamides, poly(esteramide)s, and poly(esteramine)s.

As highly branched polymer it is preferred to use a hyperbranchedpolycarbonate, poly(ethercarbonate), poly(estercarbonate) orpoly(etherestercarbonate) or a mixture of hyperbranched polymers thatcomprises at least one hyperbranched polycarbonate,poly(ethercarbonate), poly(estercarbonate) or poly(etherestercarbonate).

Hyperbranched polymers suitable for the inventive use, and processes fortheir preparation, are described in the following documents, fullyincorporated by reference:

-   -   highly branched and especially hyperbranched polycarbonates        according to WO 2005/026234,    -   hyperbranched polyesters according to WO 01/46296, DE 101 63        163, DE 102 19 508 or DE 102 40 817,    -   hyperbranched polyethers according to WO 03/062306, WO 00/56802,        DE 102 11 664 or DE 199 47 631,    -   hyperbranched polymers containing nitrogen atoms (especially        polyurethanes, polyureas, polyamides, poly(esteramides),        poly(esteramines), as described in WO 2006/087227,    -   hyperbranched polyurethanes according to WO 97/02304 or DE 199        04 444, hyperbranched poly(ureaurethanes) according to        WO97/02304 or DE 199 04 444,    -   hyperbranched polyureas as described in WO 03/066702, WO        2005/044897 and WO 2005/075541,    -   hyperbranched amino-containing polymers, especially        poly(esteramines) according to WO 2005/007726,    -   hyperbranched poly(esteramides) according to WO 99/16810 or EP 1        036 106,    -   hyperbranched polyamides as described in WO 2006/018125,    -   hyperbranched poly(estercarbonates) as described in WO        2006/089940.

Preferred polymers are those which have a weight-average molecularweight M_(w) in the range from about 500 to 500 000, preferably 750 to200 000, more particularly 1000 to 100 000. The molar mass can bedetermined by gel permeation chromatography with a standard, such aspolymethyl methacrylate.

In the context of the present invention the expression “alkyl” comprisesstraight-chain and branched alkyl groups. Suitable short-chain alkylgroups are, for example, straight-chain or branched C₁-C₇ alkyl,preferably C₁-C₆ alkyl, and more preferably C₁-C₄ alkyl groups. Theyinclude more particularly methyl, ethyl, propyl, isopropyl, n-butyl,2-butyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl,3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl,2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl,3-methylpentyl, 4-methylpentyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl,2,3-dimethylbutyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl,3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl,1-ethylbutyl, 2-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl,3-heptyl, 2-ethylpentyl, 1-propylbutyl, etc. Suitable longer-chainC₈-C₃₀ alkyl groups are straight-chain or branched alkyl groups. Theyare preferably predominantly linear alkyl radicals, of the kind alsooccurring in natural or synthetic fatty acids and fatty alcohols andalso oxo-process alcohols. They include, for example, n-octyl, n-nonyl,n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl,n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, etc. The expression“alkyl” comprises unsubstituted and substituted alkyl radicals.

The above remarks for alkyl also apply to the alkyl moieties inarylalkyl. Preferred arylalkyl radicals are benzyl and phenylethyl.

C₈-C₃₂ alkenyl in the context of the present invention stands forstraight-chain and branched alkenyl groups, which may be singly, doublyor multiply unsaturated. Preference is given to C₁₀-C₂₀ alkenyl. Theexpression “alkenyl” comprises unsubstituted and substituted alkenylradicals. The radicals in question are, especially, predominantly linearalkenyl radicals, of the kind which also occur in natural or syntheticfatty acids and fatty alcohols and also oxo-process alcohols. Theyinclude more particularly octenyl, nonenyl, decenyl, undecenyl,dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl,heptadecenyl, octadecenyl, nonadecenyl, linolyl, linolenyl, eleostearyl,and oleyl (9-octadecenyl).

The expression “alkylene” in the sense of the present invention standsfor straight-chain or branched alkanediyl groups having 1 to 7 carbonatoms, such as methylene, 1,2-ethylene, 1,3-propylene, etc.

Cycloalkyl stands preferably for C₄-C₈ cycloalkyl, such as cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl.

The expression “aryl” comprises for the purposes of the presentinvention monocyclic or polycyclic aromatic hydrocarbon radicals whichmay be unsubstituted or substituted. The expression “aryl” standspreferably for phenyl, tolyl, xylyl, mesityl, duryl, naphthyl,fluorenyl, anthracenyl, phenanthrenyl or naphthyl, more preferably forphenyl or naphthyl, it being possible for these aryl groups, in the caseof substitution, to carry generally 1, 2, 3, 4 or 5, preferably 1, 2 or3, substituents.

Suitability for the synthesis of hyperbranched polymers suitable for usein the method of the invention is possessed more particularly by whatare called AB_(x) monomers. These monomers have two different functionalgroups, A and B, which are able to react with one another to form alink. The functional group A is present only once per molecule, and thefunctional group B two or more times (e.g., AB₂ or AB₃ monomers). TheAB_(x) monomers may be incorporated fully in the form of branches intothe hyperbranched polymer; they may be incorporated as terminal groups,thus still having x free B groups; and they may be incorporated aslinear groups having (x−1) free B groups. The hyperbranched polymersobtained have a greater or lesser number of B groups, either terminallyor as side groups, depending on the degree of polymerization. Furtherdetails are found, for example, in Journal of Molecular Science, Rev.Macromol. Chem. Phys., C37(3), 555-579 (1997).

In addition to the groups that result during the synthesis of thehyperbranched structure (for example, carbonate groups in the case ofhyperbranched polycarbonates; urethane and/or urea groups in the case ofhyperbranched polyurethanes, and further groups originating from thereaction of isocyanate groups; amide groups in the case of hyperbranchedpolyamides, and so on), the hyperbranched polymers used in accordancewith the invention preferably contain at least four further functionalgroups. The maximum number of these functional groups is generally notcritical. In many cases, however, it is not more than 100. The number offunctional groups is preferably 4 to 100, especially 5 to 80, and moreespecially 6 to 50.

The further terminal functional groups of the hyperbranched polymersused in accordance with the invention are selected for example,independently of one another, from —OC(═O)OR, —COOH, —COOR, —CONH₂,—CONHR, —OH, —NH₂, —NHR, and —SO₃H. Hyperbranched polymers terminated byOH, COOH and/or ROC(═O)O— groups have proven particularly advantageous.

Hyperbranched Polycarbonates

Hyperbranched polycarbonates suitable for use for increasing the glosscan be prepared, for example, by

-   a) reacting at least one organic carbonate (A) of the general    formula R^(a)OC(═O)OR^(b) with at least one aliphatic alcohol (B)    which contains at least 3 OH groups, with elimination of alcohols    R^(a)OH and R^(b)OH, to give one or more condensation products (K),    R^(a) and R^(b) each being selected independently of one another    from straight-chain or branched alkyl, arylalkyl, cycloalkyl, and    aryl radicals, and it also being possible for R^(a) and R^(b),    together with the group —OC(═O)O— to which they are attached, to be    a cyclic carbonate,-   b) intermolecularly reacting the condensation products (K) to give a    high-functionality, hyperbranched polycarbonate,    the proportion of the OH groups to the carbonates in the reaction    mixture being chosen such that the condensation products (K) contain    on average either one carbonate group and more than one OH group, or    one OH group and more than one carbonate group. The radicals R^(a)    and R^(b) may have identical or different definitions. In one    specific version R^(a) and R^(b) have the same definitions.    Preferably R^(a) and R^(b) are selected from C₁-C₂₀ alkyl, C₅-C₇    cycloalkyl, C₆-C₁₀ aryl, and C₆-C₁₀ aryl-C₁-C₂₀, alkyl, as defined    above. R^(a) and R^(b) can also together be a C₂-C₆ alkylene group.    With particular preference R^(a) and R^(b) are selected from    straight-chain and branched C₁-C₅ alkyl, as defined above.

Dialkyl or diaryl carbonates can be prepared, for example, from thereaction of aliphatic, araliphatic or aromatic alcohols, preferablymonoalcohols, with phosgene. Furthermore, they can also be prepared viaoxidative carbonylation of the alcohols or phenols by means of CO in thepresence of noble metals, oxygen or NO_(x). Regarding preparationmethods of diaryl or dialkyl carbonates, see also Ullmann's Encyclopediaof Industrial Chemistry, 6^(th) Edition, 2000 Electronic Release,Wiley-VCH.

Examples of suitable carbonates encompass aliphatic or aromaticcarbonates such as ethylene carbonate, 1,2- or 1,3-propylene carbonate,diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, dinaphthylcarbonate, ethyl phenyl carbonate, dibenzyl carbonate, dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate,diisobutyl carbonate, dipentyl carbonate, dihexyl carbonate,dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylcarbonate, and didodecyl carbonate.

Preference is given to using aliphatic carbonates, more particularlythose in which the radicals comprise 1 to 5 C atoms, such as dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate ordiisobutyl carbonate, for example.

The organic carbonates are reacted with at least one aliphatic alcohol(B) which contains at least 3 OH groups, or with mixtures of two or moredifferent alcohols.

Examples of compounds having at least three OH groups are glycerol,trimethylolmethane, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, bis(trimethylolpropane),di(pentaerythritol), di-, tri- or oligoglycerols, or sugars, such asglucose, polyetherols that have a functionality of three or more and arebased on alcohols with a functionality of three or more and ethyleneoxide, propylene oxide or butylene oxide, or polyesterols. Particularpreference is given to glycerol, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, pentaerythritol, and also their polyetherols based onethylene oxide or propylene oxide.

These polyfunctional alcohols can also be used in a mixture ofdifunctional alcohols (B′), with the proviso that the average OHfunctionality of all of the alcohols used is together more than 2.Examples of suitable compounds having two OH groups comprise ethyleneglycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propanediol,dipropylene glycol, tripropylene glycol, neopentyl glycol, 1,2-, 1,3-,and 1,4-butanediol, 1,2-, 1,3-, and 1,5-pentanediol, hexanediol,cyclopentanediol, cyclohexanediol, cyclohexanedimethanol, anddifunctional polyetherols or polyesterols.

The reaction of the carbonate with the alcohol or alcohol mixture togive the high-functional hyperbranched polycarbonate used according tothe invention takes place with elimination of the monofunctional alcoholor phenol from the carbonate molecule.

The high-functionality hyperbranched polycarbonates formed by theprocess outlined are terminated after the reaction, i.e., withoutfurther modification, with hydroxyl groups and/or with carbonate groups.They dissolve readily in various solvents, as for example in water,alcohols, such as methanol, ethanol, butanol, alcohol/water mixtures,acetone, 2-butanone, ethyl acetate, butyl acetate, methoxypropylacetate, methoxyethyl acetate, tetrahydrofuran, dimethylformamide,dimethylacetamide, N-methylpyrrolidone, ethylene carbonate or propylenecarbonate.

By a high-functionality polycarbonate is meant in the context of thisinvention a product which besides the carbonate groups which form thepolymer backbone has terminally or pendently in addition at least four,preferably at least eight functional groups. The functional groups arecarbonate groups and/or OH groups. In principle there is no upper limiton the number of terminal or pendent functional groups; however,products having a very high number of functional groups may exhibitunwanted properties, such as high viscosity or poor solubility, forexample. The high-functionality polycarbonates of the present inventiongenerally have no more than 500 terminal or pendent functional groups,preferably not more than 100, and more particularly not more than 50terminal or pendent functional groups.

For the preparation of the high-functionality polycarbonates it isnecessary to set the ratio of the OH-comprising compounds to thecarbonate such that the resultant simplest condensation product (calledcondensation product (K) below) comprises on average either onecarbonate group and more than one OH group or one OH group and more thanone carbonate group. The simplest structure of the condensation product(K) of a carbonate (A) and a dialcohol or polyalcohol (B) produces thearrangement XY_(n) or YX_(n), X being a carbonate group, Y a hydroxylgroup and n generally an integer between 1 and 6, preferably between 1and 4, more preferably between 1 and 3. The reactive group, whichresults as a single group, is referred to below as “focal group”.

Where, for example, in the preparation of the simplest condensationproduct (K) from a carbonate and a dihydric alcohol, the reaction ratiois 1:1, then the result on average is a molecule of type XY. In the caseof the preparation of the condensation product (K) from a carbonate anda trihydric alcohol with a reaction ratio of 1:1. the result on averageis a molecule of type XY₂. In the preparation of a condensation product(K) from a carbonate and a tetrahydric alcohol, again with the reactionratio 1:1, the result on average is a molecule of type XY₃. Thecondensation product (K) can also be prepared, for example, from acarbonate and a trihydric alcohol where the reaction ratio on a molarbasis is 2:1. Here the result on average is a molecule of type X₂Y, thefocal group here being an OH group. Where the difunctional compounds,e.g. a dicarbonate of a diol, are additionally added to the components,this produces an extension of the chains. The result again is on averagea molecule of type XY₂, the focal group being a carbonate group. Thesimple condensation products (K) react in accordance with the inventionintermolecularly to form high-functionality polycondensation products(P). The reaction to give the condensation product (K) and to give thepolycondensation product (P) takes place usually at a temperature of 0to 250° C., preferably at 60 to 160° C., in bulk or in solution. In thiscontext it is possible generally to use any solvents which are inerttowards the respective reactants. Preference is given to using organicsolvents, such as, for example, decane, dodecane, benzene, toluene,chlorobenzene, xylene, dimethylformamide, dimethylacetamide or solventnaphtha.

In one preferred embodiment the condensation reaction is carried out inbulk. The monofunctional alcohol ROH or the phenol which is liberatedduring the reaction can be removed from the reaction equilibrium inorder to accelerate the reaction, such removal taking place bydistillative means, if appropriate under reduced pressure.

If distillative removal is intended, it is advisable as a general ruleto use carbonates which during the reaction give off alcohols ROH havinga boiling point of less than 140° C.

To accelerate the reaction it is also possible to add catalysts orcatalyst mixtures. Suitable catalysts are compounds which catalyzeesterification or transesterification reactions, examples being alkalimetal hydroxides, alkali metal carbonates, alkali metal hydrogencarbonates, preferably of sodium, of potassium or of cesium, tertiaryamines, guanidines, ammonium compounds, phosphonium compounds,organoaluminum, organotin, organozinc, organotitanium, organozirconiumor organobismuth compounds, and also catalysts of the kind known asdouble metal cyanide (DMC) catalysts, as described, for example, in DE10138216 or in DE 10147712.

Preference is given to using potassium hydroxide, potassium carbonate,potassium hydrogen carbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole or 1,2-dimethylimidazole, titaniumtetrabutoxide, titanium tetraisopropoxide, dibutyltin oxide, dibutyltindilaurate, tin dioctoate, zirconium acetylacetonate, or mixturesthereof.

The catalyst is generally added in an amount of 50 to 10 000 ppm byweight, preferably of 100 to 5000 ppm by weight, based on the amount ofalcohol or alcohol mixture employed.

Furthermore it is also possible, either by adding the appropriatecatalyst and/or by choosing a suitable temperature, to control theintermolecular polycondensation reaction. In addition the averagemolecular weight of the polymer (P) can be adjusted via the compositionof the starting components and via the residence time.

The condensation products (K) and the polycondensation products (P),which have been prepared at an elevated temperature, are stable at roomtemperature usually for a relatively long period of time.

In view of the nature of the condensation products (K) it is possiblethat the condensation reaction may result in polycondensation products(P) having different structures, with branches but no crosslinks.Furthermore, the polycondensation products (P) ideally contain either acarbonate focal group and more than two OH groups, or else an OH focalgroup and more than two carbonate groups. The number of reactive groupsdepends on the nature of the condensation products (K) employed and onthe degree of polycondensation. For example, a condensation product (K)may also react by triple intermolecular condensation to form twodifferent polycondensation products (P).

To terminate the intermolecular polycondensation reaction there are avariety of possibilities. By way of example the temperature can belowered to a range in which the reaction comes to a standstill and theproduct (K) or the polycondensation product (P) is stable on storage.

In a further embodiment, as soon as the intermolecular reaction of thecondensation product (K) gives a polycondensation product (P) having thedesired degree of polycondensation, the reaction can be arrested byadding to the product (P) a product having groups that are reactivetoward the focal group of (P). For instance, in the case of a carbonatefocal group, a mono-, di- or polyamine, for example, can be added. Inthe case of a hydroxyl focal group, the product (P) can have added toit, for example, a mono-, di- or polyisocyanate, a compound comprisingepoxide groups, or an acid derivative which is reactive with OH groups.

The high-functionality polycarbonates of the invention are generallyprepared in a pressure range from 0.1 mbar to 20 bar, preferably 1 mbarto 5 bar, in reactors or reactor cascades which are operated batchwise,semibatchwise or continuously.

As a result of the aforementioned setting of the reaction conditionsand, if appropriate, as a result of the choice of suitable solvent, theproducts can be processed further following preparation, withoutadditional purification.

In a further preferred embodiment the polycarbonates may comprise notonly the functional groups already obtained by virtue of the reactionbut also further functional groups. Functionalization can in this casetake place during the buildup of molecular weight or else subsequently,i.e., after the end of the actual polycondensation.

If, before or during the buildup of molecular weight, components areadded which besides hydroxyl or carbonate groups possess furtherfunctional groups or functional elements, then a polycarbonate polymeris obtained which has randomly distributed functionalities differentfrom the carbonate and hydroxyl groups.

Effects of this kind can be achieved for example by adding, during thepolycondensation, compounds which in addition to hydroxyl, carbonate orcarbamoyl chloride groups carry further functional groups or functionalelements, such as mercapto groups, primary, secondary or tertiary aminogroups, ether groups, carboxylic acid derivatives, sulfonic acidderivatives, phosphonic acid derivatives, aryl radicals or long-chainalkyl radicals. For modification by means of carbamate groups it ispossible for example to use ethanolamine, propanolamine,isopropanolamine, 2-(butylamino)ethanol, 2-(cyclohexylamino)ethanol,2-amino-1-butanol, 2-(2′-aminoethoxy)ethanol or higher alkoxylationproducts of ammonia, 4-hydroxypiperidine, 1-hydroxyethylpiperazine,diethanolamine, dipropanolamine, diisopropanolamine,tris(hydroxymethyl)aminomethane, tris(hydroxyethyl)aminomethane,ethylenediamine, propylenediamine, hexamethylenediamine orisophoronediamine.

For modification with mercapto groups it is possible to usemercaptoethanol for example. Tertiary amino groups can be generated, forexample, by incorporation of N-methyldiethanolamine,N-methyldipropanolamine or N,N-dimethylethanolamine. Ether groups can begenerated, for example, by incorporating polyetherols having afunctionality of two or more during condensation. Reaction withlong-chain alkanediols enables long-chain alkyl radicals to beincorporated; reaction with alkyl or aryl diisocyanates generatespolycarbonates containing alkyl, aryl, and urethane groups.

Subsequent functionalization can be obtained by reacting the resultanthigh-functionality hyperbranched polycarbonate with a suitablefunctionalizing reagent that is able to react with the polycarbonate'sOH and/or carbonate groups.

High-functionality, hyperbranched polycarbonates comprising hydroxylgroups can be modified, for example, by adding molecules comprising acidgroups or isocyanate groups. Polycarbonates comprising acid groups, forexample, can be obtained by reaction with compounds comprising anhydridegroups.

Additionally, high-functionality polycarbonates comprising hydroxylgroups can also be converted into high-functionalitypolycarbonate-polyetherpolyols by reaction with alkylene oxides-ethyleneoxide, propylene oxide or butylene oxide, for example.

A great advantage of the method of the invention lies in its economy.Both the reaction to form a condensation product (K) or polycondensationproduct (P) and the reaction of (K) or (P) to form polycarbonates withother functional groups or elements can take place in one reactionapparatus, which is an advantage both technically and economically.

Hyperbranched Polyesters

As hyperbranched polyesters it is preferred to use those of A₂B_(x)type. Particularly preferred are hyperbranched polyesters of A₂B₃ type.As compared with hyperbranched polyesters of the AB₂ type, these A₂B₃polyesters have a less rigid structure. Consequently hyperbranchedpolyesters of AB₂ type are less preferred.

Hyperbranched polyesters that are suitable for use for increasing thegloss are obtainable by reacting at least one aliphatic, cycloaliphatic,araliphatic or aromatic dicarboxylic acid (A₂) or derivatives thereofwith

-   a) at least one at least trifunctional aliphatic, cycloaliphatic,    araliphatic or aromatic alcohol (B₃), or-   b) with at least one divalent aliphatic, cycloaliphatic, araliphatic    or aromatic alcohol (B₂) with at least one x-valent aliphatic,    cycloaliphatic, araliphatic or aromatic alcohol (C_(x)) which    contains more than two OH groups, x being a number greater than 2,    preferably 3 to 8, more preferably 3 to 6, very preferably 3 to 4,    and more particularly 3,    or by reacting at least one aliphatic, cycloaliphatic, araliphatic    or aromatic carboxylic acid (D_(y)) or derivatives thereof    containing more than two acid groups, y being a number greater than    2, preferably 3 to 8, more preferably 3 to 6, very preferably 3 to    4, and more particularly 3, with-   c) at least one at least difunctional aliphatic, cycloaliphatic,    araliphatic or aromatic alcohol (B₂), or-   d) with at least one divalent aliphatic, cycloaliphatic, araliphatic    or aromatic alcohol (B₂) with at least one x-valent aliphatic,    cycloaliphatic, araliphatic or aromatic alcohol (C_(x)) containing    more than two OH groups, x being a number greater than 2, preferably    3 to 8, more preferably 3 to 6, very preferably 3 to 4, and more    particularly 3,-   e) if appropriate in the presence of further functionalized units E,    and-   f) optionally subsequent reaction with a monocarboxylic acid F,    the proportion of the reactive groups in the reaction mixture being    chosen so as to set a molar ratio of OH groups to carboxyl groups or    derivatives thereof of 5:1 to 1:5, preferably of 4:1 to 1:4, more    preferably of 3:1 to 1:3, and very preferably of 2:1 to 1:2.

By hyperbranched polyesters are meant for the purposes of this inventionnoncrosslinked polyesters having hydroxyl and carboxyl groups and beingboth structurally and molecularly nonuniform. Noncrosslinked for thepurpose of this specification means that the degree of crosslinkingpresent is less than 15% by weight, preferably less than 10% by weight,determined by way of the insoluble fraction of the polymer. Theinsoluble fraction of the polymer was determined by extracting for fourhours using the same solvent as employed for the gel permeationchromatography, in other words tetrahydrofuran or hexafluoroisopropanol,depending on what solvent has better solvency for the polymer, in aSoxhlet apparatus, drying of the residue to constant weight, andweighing of the remaining residue.

The dicarboxylic acids (A₂) include for example aliphatic dicarboxylicacids, such as oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelinic acid, suberic acid, azelaic acid, sebacic acid,undecane-α,ω-dicarboxylic acid, dodecane-α,ω-dicarboxylic acid, cis- andtrans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-dicarboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, cis- andtrans-cyclopentane-1,3-dicarboxylic acid. It is also possibleadditionally to use aromatic dicarboxylic acids, such as phthalic acid,isophthalic acid or terephthalic acid, for example. Unsaturateddicarboxylic acids as well, such as maleic acid or fumaric acid, can beused.

Said dicarboxylic acids may also be substituted by one or more radicalsselected from C₁-C₁₀ alkyl groups, C₃-C₁₂ cycloalkyl groups, alkylenegroups such as methylene or ethylidene or C₆-C₁₄ aryl groups. Exemplaryrepresentatives of substituted dicarboxylic acids that may be mentionedinclude the following: 2-methylmalonic acid, 2-ethylmalonic acid,2-phenylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid,2-phenylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid.

It is also possible to use mixtures of two or more of the aforementioneddicarboxylic acids.

The dicarboxylic acids can be used either as such or in the form oftheir derivatives.

C₁-C₄ alkyl specifically means methyl, ethyl, isopropyl, n-propyl,n-butyl, isobutyl, sec-butyl and tert-butyl, preferably methyl, ethyland n-butyl, more preferably methyl and ethyl, and very preferablymethyl.

It is also possible to use a mixture of a dicarboxylic acid and one ormore of its derivatives. Likewise possible is to use a mixture of two ormore different derivatives of one or more dicarboxylic acids.

Particular preference is given to using malonic acid, succinic acid,glutaric acid, adipic acid, 1,2-, 1,3- or 1,4-cyclohexanedicarboxylicacid (hexahydrophthalic acids), phthalic acid, isophthalic acid,terephthalic acid or the monoalkyl or dialkyl esters thereof.

Examples of tricarboxylic or polycarboxylic acids (D_(y)) that can bereacted include aconitic acid, 1,3,5-cyclohexanetricarboxylic acid,1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid,1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid) and alsomellitic acid and low molecular weight polyacrylic acids.

Tricarboxylic acids or polycarboxylic acids (D_(y)) can be used eitheras such or else in the form of derivatives.

Derivatives are the corresponding anhydrides in monomeric or elsepolymeric form, mono- or dialkyl ester, preferably mono- ordi-C₁-C₄-alkyl esters, more preferably mono- or dimethyl esters or thecorresponding mono- or diethyl esters, additionally mono- and divinylesters, and also mixed esters, preferably mixed esters having differentC₁-C₄ alkyl components, more preferably mixed methyl ethyl esters.

It is also possible to use a mixture of a tricarboxylic orpolycarboxylic acid and one or more of its derivatives, such as amixture of pyromellitic acid and pyromellitic dianhydride, for example.It is likewise possible to use a mixture of two or more differentderivatives of one or more tricarboxylic or polycarboxylic acids, suchas a mixture of 1,3,5-cyclohexanetricarboxylic acid and pyromelliticdianhydride, for example.

Diols (B₂) used include for example ethylene glycol, propane-1,2-diol,propane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol,butane-2,3-diol, pentane-1,2-diol, pentane-1,3-diol, pentane-1,4-diol,pentane-1,5-diol, pentane-2,3-diol, pentane-2,4-diol, hexane-1,2-diol,hexane-1,3-diol, hexane-1,4-diol, hexane-1,5-diol, hexane-1,6-diol,hexane-2,5-diol, heptane-1,2-diol, 1,7-heptanediol, 1,8-octanediol,1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol,1,2-dodecanediol, 1,12-dodecanediol, 1,5-hexadiene-3,4-diol, 1,2- and1,3-cyclopentanediols, 1,2-, 1,3- and 1,4-cyclohexanediols, 1,1-, 1,2-,1,3- and 1,4-bis(hydroxymethyl)cyclohexanes, 1,1-, 1,2-, 1,3- and1,4-bis(hydroxyethyl)cyclohexanes, neopentyl glycol,(2)-methyl-2,4-pentanediol, 2,4-dimethyl-2,4-pentanediol,2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol,2,2,4-trimethyl-1,3-pentanediol, pinacol, diethylene glycol, triethyleneglycol, dipropylene glycol, tripropylene glycol, polyethylene glycolsHO(CH₂CH₂O)_(n)—H or polypropylene glycols HO(CH[CH₃]CH₂O)_(n)—H, nbeing an integer and n≧4, polyethylene-polypropylene glycols, thesequence of the ethylene oxide or propylene oxide units being blockwiseor random, polytetramethylene glycols, preferably with a molar weight ofup to 5000 g/mol, poly-1,3-propanediols, preferably with a molar weightup to 5000 g/mol, polycaprolactones, or mixtures of two or morerepresentatives of the above compounds. Either one or both hydroxylgroups in the abovementioned diols may be substituted by SH groups.Diols whose use is preferred are ethylene glycol, 1,2-propanediol,1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,1,8-octanediol, 1,2-, 1,3- and 1,4-cyclohexanediol, 1,3- and1,4-bis(hydroxymethyl)cyclohexane, and diethylene glycol, triethyleneglycol, dipropylene glycol and tripropylene glycol, polyethylene glycolsHO(CH₂CH₂O)_(n)—H or polypropylene glycols HO(CH[CH₃]CH₂O)_(n)—H, nbeing an integer and n≧4, polyethylene-polypropylene glycols, thesequence of the ethylene oxide or propylene oxide units being blockwiseor random, or polytetramethylene glycols, preferably with a molar weightof up to 5000 g/mol.

The dihydric alcohols B₂ may optionally also comprise furtherfunctionalities such as carbonyl, carboxyl, alkoxycarbonyl or sulfonyl,for example, such as dimethylolpropionic acid or dimethylolbutyric acid,for example, and also their C₁-C₄ alkyl esters, glycerol monostearate orglycerol monooleate.

Alcohols with a functionality of at least three (C_(x)) compriseglycerol, trimethylolmethane, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, diglycerol, triglycerol orhigher condensates of glycerol, di(trimethylolpropane),di(pentaerythritol), trishydroxymethyl isocyanurate, tris(hydroxyethyl)isocyanurate (THEIC), tris(hydroxypropyl) isocyanurate, inositols orsugars, such as glucose, fructose or sucrose, for example, sugaralcohols such as sorbitol, mannitol, threitol, erythritol, adonitol(ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol,isomalt, polyetherols with a functionality of three or more, based onalcohols with a functionality of three or more and on ethylene oxide,propylene oxide and/or butylene oxide.

Particular preference is given here to glycerol, diglycerol,triglycerol, trimethylolethane, trimethylolpropane,bis(trimethylolpropane), 1,2,4-butanetriol, pentaerythritol,di(pertaerythritol), tris(hydroxyethyl) isocyanurate and alsopolyetherols thereof based on ethylene oxide and/or propylene oxide.

The reaction can be carried out in the absence or the presence of asolvent. Examples of suitable solvents include hydrocarbons such asparaffins, aromatics, ethers, and ketones. Preferably the reaction iscarried out free from solvent. It is possible to carry out the reactionin the presence of a water-removing agent, as an additive added at thebeginning of the reaction. Suitable examples include molecular sieves,especially molecular sieve 4 Å, MgSO₄ and Na₂SO₄. It is also possible toremove water and/or alcohol during the reaction, by distillation and,for example, to use a water separator, in which case the water isremoved with the aid of an entrainer.

The reaction can be carried out in the absence of catalysts. It ispreferred, however, to operate in the presence of at least one catalyst.These are preferably acidic inorganic, organometallic or organiccatalysts or mixtures of two or more acidic inorganic, organometallic ororganic catalysts.

Acidic inorganic catalysts for the purposes of the present invention arefor example sulfuric acid, sulfates, and hydrogen sulfates, such assodium hydrogen sulfate, phosphoric acid, phosphonic acid,hypophosphorous acid, aluminum sulfate hydrate, alum, acidic silica gel(pH≦6, especially ≦5), and acidic aluminum oxide. Further acidicinorganic catalysts which can be used include, for example, aluminumcompounds of the general formula Al(OR¹)₃ and titanates. Preferredacidic organometallic catalysts are for example dialkyltin oxides ordialkyltin esters. Preferred acidic organic catalysts are acidic organiccompounds containing, for example, phosphate groups, sulfonic acidgroups, sulfate groups or phosphonic acid groups. Acidic ion exchangerscan also be used as acidic organic catalysts.

The reaction is carried out at temperatures from 60 to 250° C.

The hyperbranched polyesters used in accordance with the invention havea molecular weight M_(w) of at least 500, preferably at least 600, andmore preferably 1000 g/mol. The upper limit of the molecular weightM_(w) is preferably 500 000 g/mol; with particular preference it is notmore than 200 000, and with very particular preference not more 100 000g/mol.

The figures on the polydispersity and also on the number-average andweight-average molecular weight, M_(n) and M_(w), refer here tomeasurements made by gel permeation chromatography using polymethylmethacrylate as a standard and using tetrahydrofuran, dimethylformamide,dimethylacetamide or hexafluoroisopropanol as eluant. The method isdescribed in Analytiker Taschenbuch, vol. 4, pages 433 to 442, Berlin1984.

The polydispersity of polyesters used in accordance with the inventionis generally 1.2 to 50, preferably 1.4 to 40, more preferably 1.5 to 30,and very preferably 2 to 30.

Hyperbranched Polyurethanes

As used herein, the term “polyurethanes” extends beyond the customaryunderstanding and includes polymers which are obtainable by reaction ofdi- or polyisocyanates with active-hydrogen compounds and which arelinkable together by urethane structures, but also for example by urea,allophanate, biuret, carbodiimide, amide, uretonimine, uretdione,isocyanurate or oxazolidone structures.

The hyperbranched polyurethanes used according to the invention can besynthesized using AB_(x) monomers containing not only isocyanate groupsbut also groups capable of reacting with isocyanate groups to form alinkage. To synthesize the hyperbranched polyurethanes used according tothe invention it is also possible to employ monomer combinations whichinitially, as intermediates, form AB_(x) building blocks, where x is anatural number between 2 and 8, preferably 2 or 3. Such hyperbranchedpolyurethanes and processes for preparing them are described in WO97/02304, hereby incorporated by reference. Suitable hyperbranchedpolyurethanes can also be obtained by reacting diisocyanates and/orpolyisocyanates with compounds having at least two isocyanate-reactivegroups, at least one of the reactants containing functional groups whosereactivity is different from that of the other reactant, and thereaction conditions being chosen such that in each reaction step onlycertain reactive groups react with one another in each case. Suchhyperbranched polyurethanes and processes for preparing them aredescribed in EP 1026185, hereby incorporated by reference.

The isocyanate-reactive groups are preferably OH—, NH₂—, NHR— or SHgroups.

The AB_(x) monomers are preparable in a conventional manner. AB_(x)monomers are synthesizable for example by the method described in WO97/02304 using protective group techniques. This technique may beillustrated with reference to the preparation of an AB₂ monomer from2,4-toluoylene diisocyanate (TDI) and trimethylolpropane. First, one ofthe isocyanate groups of the TDI is blocked in a conventional manner,for example by reaction with an oxime. The remaining free NCO group isreacted with trimethylolpropane, although only one of the three OHgroups reacts with the isocyanate group, the other two OH groups beingblocked via acetalization. Elimination of the protective group leaves amolecule having one isocyanate group and two OH groups.

A particularly advantageous way to synthesize AB_(x) molecules is by themethod described in DE-A 199 04 444, where no protective groups arerequired. Di- or polyisocyanates are used in this method and reactedwith compounds having at least two isocyanate-reactive groups. At leastone of the reactants has groups having a reactivity that differs withregard to the other reactant. Preferably, both reactants have groupsthat differ in reactivity with regard to the other reactant. Thereaction conditions are chosen in such a way that only certain reactivegroups can react with each other.

Useful di- and polyisocyanates include the aliphatic, cycloaliphatic andaromatic isocyanates known from the prior art. Preferred di- orpolyisocyanates are 4,4′-diphenylmethane diisocyanate, the mixtures ofmonomeric diphenylmethane diisocyanates and oligomeric diphenylmethanediisocyanates (polymer MDI), tetramethylene diisocyanate, hexamethylenediisocyanate, 4,4′-methylenebis(cyclohexyl) diisocyanate, xylylenediisocyanate, tetramethylxylylene diisocyanate, dodecyl diisocyanate,lysine alkyl ester diisocyanate, where alkyl is C₁-C₁₀ alkyl, 2,2,4- or2,4,4-trimethyl-1,6-hexamethylene diisocyanate,1,4-diisocyanatocyclohexane or 4-isocyanatomethyl-1,8-octamethylenediisocyanate.

Particular preference is given to di- or polyisocyanates having NCOgroups of different reactivities, such as 2,4-toluoylene diisocyanate(2,4-TDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI),triisocyanatotoluene, isophorone diisocyanate (IPDI),2-butyl-2-ethylpentamethylene diisocyanate, 2-isocyanatopropylcyclohexylisocyanate, 3(4)-isocyanatomethyl-1-methylcyclohexyl isocyanate,1,4-diisocyanato-4-methylpentane, 2,4′-methylenebis(cyclohexyl)diisocyanate and 4-methylcyclohexane 1,3-diisocyanate (H-TDI).Particular preference is further given to isocyanates (b) whose NCOgroups initially have equal reactivity, but where first addition of analcohol or amine to an NCO group can be used to induce a reactivityreduction for the second NCO group. Examples thereof are isocyanateswhose NCO groups are coupled via a delocalized electron system, forexample 1,3- and 1,4-phenylene diisocyanate, 1,5-naphthylenediisocyanate, diphenyl diisocyanate, tolidine diisocyanate or2,6-toluoylene diisocyanate.

It is further possible to use for example oligo- or polyisocyanatespreparable from the di- or polyisocyanates mentioned or mixtures thereofby linkage by means of urethane, allophanate, urea, biuret, uretdione,amide, isocyanurate, carbodiimide, uretonimine, oxadiazinetrione oriminooxadiazinedione structures.

Compounds used as having at least two isocyanate-reactive groups arepreferably di-, tri- or tetrafunctional compounds whose functionalgroups have different reactivities toward NCO groups. Preference isgiven to compounds having at least one primary and at least onesecondary hydroxyl group, at least one hydroxyl group and at least onemercapto group, particularly preferably having at least one hydroxylgroup and at least one amino group in the molecule, especially aminoalcohols, aminodiols and aminotriols, since amino is substantially morereactive with isocyanate than is hydroxyl.

Examples of said compounds having at least two isocyanate-reactivegroups are propylene glycol, glycerol, mercaptoethanol, ethanolamine,N-methylethanolamine, diethanolamine, ethanolpropanolamine,dipropanolamine, diisopropanolamine, 2-amino-1,3-propanediol,2-amino-2-methyl-1,3-propanediol or tris(hydroxmethyl)aminomethane.Mixtures of the compounds mentioned may also be used.

The preparation of an AB₂ molecule may be illustrated for a diisocyanatewith an aminodiol. First one mole of a diisocyanate is reacted with onemole of aminodiol at low temperatures, preferably in the range from −10to 30° C. The urethane-forming reaction is virtually completelysuppressed in this temperature range and the more reactive NCO groups ofthe isocyanate react exclusively with the amino group of the aminodiol.The AB_(x) molecule formed has one free NCO group and two free OH groupsand can be used for synthesizing a highly branched polyurethane.

On heating and/or catalyst addition this AB₂ molecule can reactintermolecularly to form a highly branched polyurethane. The synthesisof the hyperbranched polyurethane may advantageously be effected withoutprior isolation of the AB_(x) molecule in a further reaction step atelevated temperature, preferably in the range between 30 and 80° C.Using the above-described AB₂ molecule having two OH groups and one NCOgroup provides a hyperbranched polymer having per molecule one free NCOgroup and also—depending on the degree of polymerization—a certainnumber of OH groups. The reaction can be carried on to high conversionsto provide very high molecular weight structures. But it may also bediscontinued for example by addition of suitable monofunctionalcompounds or by addition of one of the starting compounds for preparingthe AB₂ molecule on attainment of the desired molecular weight.Depending on the starting compound used for the termination, thisprovides either completely NCO-terminated or completely OH-terminatedmolecules.

Alternatively, it is also possible for example to prepare an AB₂molecule from one mole of glycerol and 2 mol of 2,4-TDI. The primaryalcohol groups and the isocyanate group in position 4 reactpreferentially at low temperature to form an adduct which has one OHgroup and two isocyanate groups and which, as described, can beconverted at higher temperatures into a hyperbranched polyurethane. Thisinitially provides a hyperbranched polymer which has one free OH groupand—depending on the degree of polymerization—a certain number of NCOgroups.

The hyperbranched polyurethanes may in principle be prepared withoutsolvent, but are preferably prepared in solution. Useful solventsinclude in principle all compounds that are liquid at room temperatureand inert toward the monomers and polymers.

Other products are obtainable through further synthetic variants. AB₃molecules are obtainable for example by reacting diisocyanates withcompounds having at least 4 isocyanate-reactive groups. An example isthe reaction of 2,4-toluoylene diisocyanate withtris(hydroxymethyl)aminomethane.

The polymerization may also be terminated using polyfunctional compoundscapable of reacting with the respective A groups. This makes it possibleto link a plurality of small hyperbranched molecules together to form alarge hyperbranched molecule.

Hyperbranched polyurethanes having chain-extended branches areobtainable for example by using for the polymerization reaction as wellas the AB_(x) molecules additionally in a molar ratio of 1:1 adiisocyanate and a compound having two isocyanate-reactive groups. Theseadditional AA or BB compounds may also have further functional groupswhich, however, must not be reactive toward the A or B groups under thereaction conditions chosen. This makes it possible to introduce furtherfunctionalities into the hyperbranched polymer

Further synthetic variants for hyperbranched polyurethanes are disclosedin DE 100 13 187 and DE 100 30 869.

As stated above, the functional groups of the hyperbranchedpolyurethanes obtained by synthesis reaction may also behydrophobicized, hydrophilicized or transfunctionalized. Owing to theirreactivity, hyperbranched polyurethanes containing isocyanate groups arevery particularly useful for transfunctionalization. It is also possibleto transfunctionalize OH- or NH₂-terminated polyurethanes by means ofsuitable reaction partners.

Preferred groups for introduction into hyperbranched polyurethanes are—COON, —CONH₂, —OH, —NH₂, —NHR, —NR₂, —NR₃ ⁺, —SO₃H, and their salts.

Groups having sufficiently acidic H atoms are convertible into thecorresponding salts by treatment with suitable bases. Similarly, basicgroups are convertible into the corresponding salts using suitableacids. This makes it possible to obtain hyperbranched polyurethanes thatare soluble in water.

By reacting NCO-terminated products with alcohols and amines, especiallyalcohols and amines having C₈-C₄₀-alkyl radicals, it is possible toobtain hydrophobicized products.

Hydrophilicized but nonionic products are obtainable by reaction ofNCO-terminated polymers with polyether alcohols, for example di-, tri-or tetra- or polyethylene glycol.

Acid groups are incorporable for example by reaction withhydroxycarboxylic acids, hydroxysulfonic acids or amino acids. Examplesof suitable reaction partners are 2-hydroxyacetic acid, 4-hydroxybenzoicacid, 12-hydroxydodecanoic acid, 2-hydroxyethanesulfonic acid, glycineor alanine.

It is also possible to generate hyperbranched polyurethanes havingdifferent functionalities. This can be accomplished for example byreaction with a mixture of various compounds or else by reacting only aportion of the functional groups originally present, for example only aportion of the OH and/or NCO groups.

The transfunctionalization of the hyperbranched polyurethane mayadvantageously be effected immediately following the polymerizationreaction without the NCO-terminated polyurethane being isolatedbeforehand. But the functionalization may also take place in a separatereaction.

The hyperbranched polyurethanes used according to the inventiongenerally have on average at least 4 and not more than 100 functionalgroups. The hyperbranched polyurethanes preferably have 8 to 80, morepreferably 8 to 50, functional groups. Preferably used hyperbranchedpolyurethanes have a weight-average molecular weight M_(W) of from 1000to 500 000 g/mol, preferably of from 5000 to 200 000 g/mol, morepreferably of 10 000 to 100 000 g/mol.

Hyperbranched Polyureas

High-functionality hyperbranched polyureas which can be used inventivelyas constituents for increasing the gloss can be obtained, for example,by reacting one or more carbonates with one or more amines having atleast two primary and/or secondary amino groups, where at least oneamine has at least three primary and/or secondary amino groups.

Suitable carbonates are aliphatic, aromatic or mixed aliphatic-aromaticcarbonates; preference is given to aliphatic carbonates such as dialkylcarbonates having C₁-C₁₂ alkyl radicals. Examples are ethylenecarbonate, 1,2- or 1,3-propylene carbonate, diphenyl carbonate, ditolylcarbonate, dinaphthyl carbonate, ethyl phenyl carbonate, dibenzylcarbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate,dibutyl carbonate, diisobutyl carbonate, dipentyl carbonate, dihexylcarbonate, diheptyl carbonate, dioctyl carbonate, didecyl carbonate ordidodecyl carbonate. Carbonates used with particular preference aredimethyl carbonate, diethyl carbonate, dibutyl carbonate, and diisobutylcarbonate.

The carbonates are reacted with one or more amines having at least twoprimary and/or secondary amino groups, at least one amine having atleast three primary and/or secondary amino groups. Amines having twoprimary and/or secondary amino groups produce a chain extension withinthe polyureas, whereas amines having three or more primary or secondaryamino groups are responsible for the branching in the resultanthigh-functionality, hyperbranched polyureas.

Suitable amines having two primary or secondary amino groups which arereactive toward a carbonate or carbamate group are for exampleethylenediamine, N-alkyl-ethylenediamine, propylenediamine,2,2-dimethyl-1,3-propylenediamine, N-alkyl-propylenediamine,butylenediamine, N-alkylbutylenediamine, pentanediamine,hexamethylenediamine, N-alkylhexamethylenediamine, heptanediamine,octanediamine, nonanediamine, decanediamine, dodecanediamine,hexadecanediamine, tolylenediamine, xylylenediamine,diaminodiphenylmethane, diaminodicyclo-hexylmethane, phenylenediamine,cyclohexylenediamine, bis(aminomethyl)-cyclohexane, diaminodiphenylsulfone, isophoronediamine, 2-butyl-2-ethyl-1,5-penta-methylenediamine,2,2,4- or 2,4,4-trimethyl-1,6-hexamethylenediamine,2-aminopropyl-cyclohexylamine, 3(4)-aminomethyl-1-methylcyclohexylamine,1,4-diamino-4-methyl-pentane, amine-terminated polyoxyalkylene polyols(known as Jeffamines) or amine-terminated polytetramethylene glycols.

The amines preferably have two primary amino groups, such as, forexample, ethylenediamine, propylenediamine,2,2-dimethyl-1,3-propanediamine, butylene-diamine, pentanediamine,hexamethylenediamine, heptanediamine, octanediamine, nonanediamine,decanediamine, dodecanediamine, hexadecanediamine, tolylenediamine,xylylenediamine, diaminodiphenylmethane, diamino-dicyclohexylmethane,phenylenediamine, cyclohexylenediamine, diaminodiphenyl sulfone,isophoronediamine, bis(aminomethyl)cyclohexane,2-butyl-2-ethyl-1,5-pentamethylenediamine, 2,2,4- or2,4,4-trimethyl-1,6-hexamethylenediamine, 2-aminopropylcyclohexylamine,3(4)-aminomethyl-1-methylcyclohexylamine, 1,4-diamino-4-methylpentane,amine-terminated polyoxyalkylene polyols (known as Jeffamines) oramine-terminated polytetramethylene glycols.

Particular preference is given to butylenediamine, pentanediamine,hexamethylenediamine, tolylenediamine, xylylenediamine,diaminodiphenylmethane, diaminodicyclohexylmethane, phenylenediamine,cyclohexylenediamine, diaminodiphenyl sulfone, isophoronediamine,bis(aminomethyl)cyclohexane, amine-terminated polyoxyalkylene polyols(known as Jeffamines) or amine-terminated polytetramethylene glycols.

Suitable amines having three or more primary and/or secondary aminogroups which are reactive toward a carbonate or carbamate group are forexample tris(aminoethyl)amine, tris(aminopropyl)amine,tris(aminohexyl)amine, trisaminohexane,4-aminomethyl-1,8-octamethylenediamine, trisaminononane,bis(aminoethyl)amine, bis(aminopropyl)amine, bis(aminobutyl)amine,bis(aminopentyl)amine, bis(aminohexyl)amine,N-(2-aminoethyl)propanediamine, melamine, oligomericdiaminodiphenylmethanes, N,N′-bis(3-aminopropyl)ethylenediamine,N,N′-bis(3-aminopropyl)butanediamine,N,N,N′,N′-tetra(3-aminopropyl)ethylenediamine,N,N,N′,N′-tetra(3-aminopropyl)butylenediamine, amine-terminatedpolyoxyalkylene-polyols with a functionality of three or more (known asJeffamines), polyethyleneimines with a functionality of three or more,or polypropyleneimines with a functionality of three or more.

Preferred amines having three or more reactive primary and/or secondaryamino groups are tris(aminoethyl)amine, tris(aminopropyl)amine,tris(aminohexyl)amine, trisaminohexane,4-aminomethyl-1,8-octamethylenediamine, trisaminononane,bis(aminoethyl)amine, bis(aminopropyl)amine, bis(aminobutyl)amine,bis(aminopentyl)-amine, bis(aminohexyl)amine,N-(2-aminoethyl)propanediamine, melamine or amine-terminatedpolyoxyalkylene polyols having a functionality of three or more (knownas Jeffamines).

Particular preference is given to amines having three or more primaryamino groups, such as tris(aminoethyl)amine, tris(aminopropyl)amine,tris(aminohexyl)amine, trisaminohexane,4-aminomethyl-1,8-octamethylenediamine, trisaminononane oramine-terminated polyoxyalkylene polyols having a functionality of threeor more (known as Jeffamines).

It will be appreciated that mixtures of said amines can also be used.

In general not only amines having two primary or secondary amino groupsbut also amines having three or more primary or secondary amino groupsare used. Amine mixtures of this kind can also be characterized by theaverage amine functionality, with unreactive tertiary amino groupsdisregarded. Thus for example an equimolar mixture of a diamine and atriamine has an average functionality of 2.5. Preference is given to thereaction in accordance with the invention of amine mixtures in which theaverage amine functionality is from 2.1 to 10, in particular from 2.1 to5.

The reaction of the carbonate with the diamine or polyamine to form theinventively used high-functionality hyperbranched polyurea isaccompanied by elimination of the alcohol or phenol bound in thecarbonate. If one molecule of carbonate reacts with two amino groupsthen two molecules of alcohol or phenol are eliminated and one ureagroup is formed. If one molecule of carbonate reacts with only one aminogroup then a carbamate group is formed with elimination of a molecule ofalcohol or phenol.

The reaction of the carbonate or carbonates with the amine or amines cantake place in a solvent. In that case it is possible in general to useany solvents which are inert toward the respective reactants. Preferenceis given to working in organic solvents, such as decane, dodecane,benzene, toluene, chlorobenzene, dichlorobenzene, xylene,dimethylformamide, dimethylacetamide or solvent naphtha.

In one preferred embodiment the reaction is carried out in bulk, i.e.,without inert solvent. The alcohol or phenol liberated during thereaction between amine and carbonate or carbamate can be separated offby distillation, if appropriate under reduced pressure, and thus removedfrom the reaction equilibrium. This also accelerates the reaction.

In order to accelerate the reaction between amine and carbonate orcarbamate it is also possible to add catalysts or catalyst mixtures.Suitable catalysts are generally compounds which catalyze the formationof carbamate or urea, examples being alkali metal or alkaline earthmetal hydroxides, alkali metal or alkaline earth metal hydrogencarbonates, alkali metal or alkaline earth metal carbonates, tertiaryamines, ammonium compounds, or organic compounds of aluminum, tin, zinc,titanium, zirconium or bismuth. By way of example it is possible to uselithium, sodium, potassium or cesium hydroxide, lithium, sodium,potassium or cesium carbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole, 2-methylimidazole, and1,2-dimethylimidazole, titanium tetrabutoxide, dibutyltin oxide,dibutyltin dilaurate, tin dioctoate, zirconium acetylacetonate ormixtures thereof.

The addition of the catalyst is made generally in an amount of from 50to 10 000 ppm, preferably from 100 to 5000 ppm, by weight based on theamount of amine used.

Following the reaction, in other words without further modification, thehigh-functionality hyperbranched polyureas prepared in this way areterminated with either amino groups or carbamate groups. They dissolvereadily in polar solvents, such as in water, alcohols, such as methanol,ethanol, butanol, alcohol/water mixtures, dimethylformamide,dimethylacetamide, N-methylpyrrolidone, ethylene carbonate or propylenecarbonate.

A high-functionality hyperbranched polyurea for the purposes of theinvention is a product which has urea groups and also at least four,preferably at least six, in particular at least eight functional groups.There is in principle no upper limit on the number of functional groups,although products with a very large number of functional groups mayexhibit unwanted properties, such as a high viscosity or a poorsolubility. The high-functionality polyureas used inventively generallydo not have more than 100 functional groups, preferably not more than 30functional groups. By functional groups here are meant primary,secondary or tertiary amino groups or carbamate groups. In addition itis possible for the high-functionality hyperbranched polyurea to containfurther functional groups, which do not participate in the synthesis ofthe hyperbranched polymer (see below). These further functional groupscan be introduced by means of diamines or polyamines which containfurther functional groups in addition to primary and secondary aminogroups.

The polyureas used inventively may comprise other functional groups.Functionalization can in that case be effected during the reaction ofthe carbonate with the amine or amines, in other words during thepolycondensation reaction which produces the increase in molecularweight, or else after the end of the polycondensation reaction, bysubsequent functionalization of the resulting polyureas.

If before or during the molecular weight build-up components are addedwhich as well as amino groups or carbamate groups contain furtherfunctional groups, then the product is a polyurea having randomlydistributed further—that is, other than the carbamate groups or aminogroups—functional groups.

By way of example, before or during the polycondensation, components canbe added which in addition to amino groups or carbamate groups containhydroxyl groups, mercapto groups, tertiary amino groups, ether groups,carboxyl groups, sulfonic acid groups, phosphonic acid groups, arylradicals or long-chain alkyl radicals.

Hydroxyl-containing components which can be added for functionalizationcomprise for example ethanolamine, N-methylethanolamine, propanolamine,isopropanolamine, butanolamine, 2-amino-1-butanol,2-(butylamino)ethanol, 2-(cyclohexylamino)ethanol,2-(2′-aminoethoxy)ethanol or higher alkoxylation products of ammonia,4-hydroxypiperidine, 1-hydroxyethylpiperazine, diethanolamine,dipropanolamine, diisopropanolamine, tris(hydroxymethyl)aminomethane ortris(hydroxyethyl)aminomethane.

Mercapto-comprising components which can be added for functionalizationcomprise, for example, cysteamine. With tertiary amino groups it ispossible to functionalize the hyperbranched polyureas through the use,for example, of N-methyldiethylenetriamine orN,N-dimethylethylenediamine. With ether groups it is possible tofunctionalize the hyperbranched polyureas by using amine-terminatedpolyetherols (known as Jeffamines). With acid groups it is possible tofunctionalize the hyperbranched polyureas through the use, for example,of aminocarboxylic acids, aminosulfonic acids or aminophosphonic acids.With long-chain alkyl radicals the hyperbranched polyureas can befunctionalized by using alkylamines or alkyl isocyanates havinglong-chain alkyl radicals.

The polyureas can also be functionalized, furthermore, by using smallamounts of monomers which contain functional groups different from aminogroups or carbamate groups. Mention may be made here by way of exampleof alcohols with a functionality of two, three or more, which can beincorporated into the polyurea by way of carbonate or carbamatefunctions. Thus, for example, hydrophobic properties can be obtained byadding long-chain alkanediols, alkenediols or alkynediols, whilepolyethylene oxide diols or triols produce hydrophilic properties in thepolyurea.

The said functional groups other than amine, carbonate or carbamategroups that are introduced before or during the polycondensation aregenerally introduced in amounts of from 0.1 to 80 mol %, preferably inamounts of from 1 to 50 mol %, based on the sum of the amino, carbamate,and carbonate groups.

Subsequent functionalization of high-functionality hyperbranchedpolyureas comprising amino groups can be achieved for example by addingmolecules comprising acid groups, isocyanate groups, keto groups oraldehyde groups or molecules comprising activated double bonds, acrylicdouble bonds for example. By way of example it is possible to obtainpolyureas comprising acid groups by reaction with acrylic acid or maleicacid and derivatives thereof, with subsequent hydrolysis if appropriate.

Additionally it is possible to convert high-functionality hyperbranchedpolyureas comprising amino groups into high-functionality polyureapolyols by reaction with alkylene oxides, for example ethylene oxide,propylene oxide or butylene oxide.

The formation of salts with protic acids or quaternization of the aminofunctions with alkylating reagents, such as methyl halides or dialkylsulfates, allows the high-functionality, hyperbranched polyureas to bemade water-soluble or water-dispersible.

In order to achieve hydrophobicization it is possible foramine-terminated high-functionality hyperbranched polyureas to bereacted with saturated or unsaturated long-chain carboxylic acids, theirderivatives that are reactive toward amine groups, or else with aaliphatic or aromatic isocyanates.

Polyureas terminated with carbamate groups can be hydrophobicized byreaction with long-chain alkyl amines or long-chain aliphaticmonoalcohols.

Hyperbranched Polyamides

Suitable hyperbranched polyamides are preparable by reacting a firstmonomer A₂ having at least two functional groups A with a second monomerB₃ having at least three functional groups B, where

-   1) the functional groups A and B react with one another, and-   2) one of the monomers A and B is an amine and the other of the    monomers A and B is a carboxylic acid or an acrylate.

Suitable hyperbranched polyamides include hyperbranched polyamidoamines(see EP-A 802 215, US 2003/0069370 A1 and US 2002/0161113 A1).

Although the first monomer A₂ can also have more than two functionalgroups A, it is here termed A₂ for simplicity, and although the secondmonomer B₃ can also have more than three functional groups B it is heretermed B₃ for simplicity. The important factor is simply that thefunctionalities of A₂ and B₃ are different.

According to condition 1), the functional groups A and B react with oneanother. The selection of the functional groups A and B is thereforesuch that A does not react with A (or reacts only to an insubstantialextent) and B does not react with B (or reacts only to an insubstantialextent), but A reacts with B.

According to condition 2), one of the monomers A and B is an amine andthe other of the monomers A and B is a carboxylic acid.

Preferably, the monomer A₂ is a carboxylic acid having at least twocarboxy groups, and the monomer B₃ is an amine having at least threeamino groups. As an alternative the monomer A₂ is an amine having atleast two amino groups, and the monomer B₃ is a carboxylic acid havingat least three carboxy groups.

Suitable carboxylic acids usually have from 2 to 4, in particular 2 or3, carboxy groups, and have an alkyl, aryl, or arylalkyl radical havingfrom 1 to 30 C atoms.

Examples of dicarboxylic acids which may be used are: oxalic acid,malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,suberic acid, azelaic acid, sebacic acid, undecane-α,ω-dicarboxylicacid, dodecane-α,ω-dicarboxylic acid, cis- andtrans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-dicarboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, and also cis- andtrans-cyclopentane-1,3-dicarboxylic acid, and the dicarboxylic acidshere may have substitution by one or more radicals selected from: C₁-C₁₀alkyl groups, C₃-C₁₂ cycloalkyl groups, alkylene groups, and C₆-C₁₄ arylgroups. Examples which may be mentioned of substituted dicarboxylicacids are: 2-methylmalonic acid, 2-ethylmalonic acid, 2-phenylmalonicacid, 2-methylsuccinic acid, 2-ethylsuccinic acid, 2-phenylsuccinicacid, itaconic acid, and 3,3-dimethylglutaric acid.

Other suitable compounds are ethylenically unsaturated dicarboxylicacids, such as maleic acid and fumaric acid, and also aromaticdicarboxylic acids, such as phthalic acid, isophthalic acid, orterephthalic acid.

Examples of suitable tricarboxylic acids or tetracarboxylic acids aretrimesic acid, trimellitic acid, pyromellitic acid, butanetricarboxylicacid, naphthalenetricarboxylic acid, and cyclohexane-1,3,5-tricarboxylicacid.

It is also possible to use mixtures of two or more of the abovementionedcarboxylic acids. The carboxylic acids may either be used as they standor in the form of derivatives. These derivatives are in particular

-   -   the anhydrides of the carboxylic acids mentioned, and        specifically in monomeric or else polymeric form;    -   the esters of the carboxylic acids mentioned, e.g.,        -   mono- or dialkyl esters, preferably mono- or dimethyl            esters, or the corresponding mono- or diethyl esters, or            else the mono- and dialkyl esters derived from higher            alcohols, such as n-propanol, isopropanol, n-butanol,            isobutanol, tert-butanol, n-pentanol, n-hexanol,        -   mono- and divinyl esters, and also        -   mixed esters, preferably methyl ethyl esters.

It is also possible to use a mixture composed of a carboxylic acid andof one or more of its derivatives, or a mixture of two or more differentderivatives of one or more dicarboxylic acids.

The carboxylic acid used more preferably comprises succinic acid,glutaric acid, adipic acid, cyclohexanedicarboxylic acids, phthalicacid, isophthalic acid, terephthalic acid, or mono- or dimethyl estersthereof. Succinic acid and adipic acid are very particularly preferred.

Suitable amines usually have from 2 to 6, in particular from 2 to 4,amino groups, and an alkyl, aryl, or arylalkyl radical having from 1 to30 C atoms.

Examples of diamines which may be used are those of the formulaR¹—NH—R²—NH—R³, where R¹, R², and R³, independently of one another, arehydrogen or an alkyl, aryl, or arylalkyl radical having from 1 to 20 Catoms. The alkyl radical may be linear or in particular for R² may alsobe cyclic.

Examples of suitable diamines are ethylenediamine, the propylenediamines(1,2-diaminopropane and 1,3-diaminopropane), N-methylethylenediamine,piperazine, tetramethylenediamine (1,4-diaminobutane),N,N′-dimethylethylenediamine, N-ethylethylenediamine,1,5-diaminopentane, 1,3-diamino-2,2-diethylpropane,1,3-bis(methylamino)propane, hexamethylenediamine (1,6-diaminohexane),1,5-diamino-2-methylpentane, 3-(propylamino)propylamine,N,N′-bis(3-aminopropyl)piperazine, N,N′-bis(3-aminopropyl)piperazine,and isophoronediamine (IPDA).

Examples of suitable triamines, tetramines, or higher-functionalityamines are tris(2-aminoethyl)amine, tris(2-aminopropyl)amine,diethylenetriamine (DETA), triethylenetetramine (TETA),tetraethylenepentamine (TEPA), isopropylenetriamine,dipropylenetriamine, and N,N′-bis(3-aminopropylethylenediamine).

Aminobenzylamines and aminohydrazides having 2 or more amino groups arelikewise suitable.

The amines used particularly preferably comprise DETA ortris(2-aminoethyl)amine or a mixture of these.

It is also possible to use a mixture of two or more carboxylic acids orcarboxylic acid derivatives, or a mixture of two or more amines. Thefunctionality of the various carboxylic acids or amines here may beidentical or different.

In particular, if the monomer A₂ is a diamine, the monomer B₃ used maycomprise a mixture of dicarboxylic acids and tricarboxylic acids (orhigher-functionality carboxylic acids), the average functionality of themixture B₃ being at least 2.1. By way of example, a mixture composed of50 mol % of dicarboxylic acid and 50 mol % of tricarboxylic acid has anaverage functionality of 2.5.

Similarly, if the monomer A₂ is a dicarboxylic acid, the monomer B₃ usedmay comprise a mixture of diamines and triamines (orhigher-functionality amines), the average functionality of the mixtureB₃ being at least 2.1. This variant is particularly preferred. By way ofexample, a mixture composed of 50 mol % of diamine and 50 mol % oftriamine has an average functionality of 2.5.

The reactivity of the functional groups A of the monomer A₂ may beidentical or different. Equally, the reactivity of the functional groupsB of the monomer B₃ may be identical or different. In particular, thereactivity of the two amino groups of the monomer A₂ or of the threeamino groups of the monomer B₃ may be identical or different.

In one preferred embodiment, the carboxylic acid is the difunctionalmonomer A₂ and the amine is the trifunctional monomer B₃, and this meansthat it is preferable to use dicarboxylic acids and triamines orhigher-functionality amines.

The monomer A₂ used more preferably comprises a dicarboxylic acid, andthe monomer B₃ used more preferably comprises a triamine. The monomer A₂used very preferably comprises adipic acid and the monomer B₃ used verypreferably comprises diethylenetriamine or tris(2-aminoethyl)amine.

During or after the polymerization of the monomers A₂ and B₃ to give thehyperbranched polyamide, use may also be made of difunctional orhigher-functionality monomers C acting as chain extenders. This allowscontrol over the gel point of the polymer (juncture at which insolublegel particles are formed via crosslinking reactions; see by way ofexample Flory, Principles of Polymer Chemistry, Cornell UniversityPress, 1953, pp. 387-398), and modification of the architecture of themacromolecule, i.e., the linkage of the monomer branches.

Accordingly, one preferred embodiment of the method also makes use,during or after the reaction of the monomers A₂ and B₃, of a monomer Cacting as chain extender.

Examples of suitable chain-extending monomers C are the abovementioneddiamines or higher-functionality amines, which react with the carboxygroups of different polymer branches and thus bond them. Particularlysuitable compounds are isophoronediamine, ethylenediamine,1,2-diaminopropane, 1,3-diaminopropane, N-methylethylenediamine,piperazine, tetramethylenediamine (1,4-diaminobutane),N,N′-dimethylethylenediamine, N-ethylethylenediamine,1,5-diaminopentane, 1,3-diamino-2,2-diethylpropane,1,3-bis(methylamino)propane, hexamethylenediamine (1,6-diaminohexane),1,5-diamino-2-methylpentane, 3-(propylamino)propylamine,N,N′-bis(3-aminopropyl)piperazine, N,N′-bis(3-aminopropyl)piperazine andisophoronediamine (IPDA).

Amino acids of the general formula H₂N—R—COOH are also suitable as chainextenders C, R here being an organic radical.

The amount of the chain extenders C depends in the usual way on thedesired gel point or the desired architecture of the macromolecule. Theamount of the chain extenders C is generally from 0.1% to 50% by weight,preferably from 0.5 to 40% by weight, and in particular from 1% to 30%by weight, based on the entirety of the monomers A₂ and B₃ used.

To prepare functionalized polyamides, concomitant use is made ofmonofunctional comonomers D, which may be added prior to, during orafter the reaction of the monomers A₂ and B₃. This method gives apolymer chemically modified by the comonomer units and their functionalgroups.

One preferred embodiment of the method therefore makes use, prior to,during, or after the reaction of the monomers A₂ and B₃, of a comonomerD having a functional group, giving a modified polyamide.

Examples of these comonomers D are saturated or unsaturatedmonocarboxylic acids, including fatty acids, and their anhydrides oresters. Examples of suitable acids are acetic acid, propionic acid,butyric acid, valeric acid, isobutyric acid, trimethylacetic acid,caproic acid, caprylic acid, heptanoic acid, capric acid, pelargonicacid, lauric acid, myristic acid, palmitic acid, montanic acid, stearicacid, isostearic acid, nonanoic acid, 2-ethylhexanoic acid, benzoicacid, and unsaturated monocarboxylic acids, such as methacrylic acid,and also the anhydrides and esters, such as acrylic esters ormethacrylic esters, of the monocarboxylic acids mentioned.

Examples of suitable unsaturated fatty acids D are oleic acid,ricinoleic acid, linoleic acid, linolenic acid, erucic acid, and fattyacids derived from soy, linseed, castor oil, and sunflower.

Particularly suitable carboxylic esters D are methyl methacrylate,hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

Other comonomers D which may be used are alcohols, including fattyalcohols, e.g., glycerol monolaurate, glycerol monostearate, ethyleneglycol monomethyl ether, the polyethylene monomethyl ethers, benzylalcohol, 1-dodecanol, 1-tetradecanol, 1-hexadecanol, and unsaturatedfatty alcohols.

Other suitable comonomers D are acrylates, in particular alkylacrylates, such as n-butyl acrylate, isobutyl acrylate, tert-butylacrylate, lauryl acrylate, stearyl acrylate, or hydroxyalkyl acrylates,such as hydroxyethyl acrylate, hydroxypropyl acrylate, and thehydroxybutyl acrylates. The acrylates may be introduced in aparticularly simple manner into the polymer via Michael addition at theamino groups of the hyperbranched polyamide.

The amount of the comonomers D depends in the usual way on the extent towhich the polymer is to be modified. The amount of the comonomers D isgenerally from 0.5% to 40% by weight, preferably 1% to 35% by weight,based on the entirety of the monomers A₂ and B₃ used.

Depending on the nature and amount of the monomers used, and on thereaction conditions, the hyperbranched polyamide may have terminalcarboxy groups (—COOH) or terminal amino groups (—NH, —NH₂), or both.The selection of the comonomer D added for functionalization depends inthe usual way on the nature and number of the terminal groups with whichD reacts. If carboxy end groups are to be modified, it is preferable touse from 0.5 to 2.5, preferably from 0.6 to 2, and particularlypreferably from 0.7 to 1.5, molar equivalents of an amine, e.g. of amono- or diamine, and in particular of a triamine having primary orsecondary amino groups, per mole of carboxy end groups.

If amino end groups are to be modified, it is preferable to use from 0.5to 2.5, preferably from 0.6 to 2, and particularly preferably from 0.7to 1.5, molar equivalents of a monocarboxylic acid per mole of amino endgroups.

As mentioned, Michael addition may also be used to react amino endgroups with the acrylates mentioned, the number of acrylate molarequivalents used for this purpose preferably being from 0.5 to 2.5, inparticular from 0.6 to 2, and more preferably from 0.7 to 1.5, per moleof amino end groups.

The number of free COOH groups in (acid number of) the final polyamideproduct is generally from 0 to 400, preferably from 0 to 200, mg KOH pergram of polymer and may be determined, for example, via titration to DIN53240-2.

The monomers A₂ are generally reacted with the monomers B₃ at anelevated temperature, for example at from 80 to 180° C., in particularfrom 90 to 160° C. It is preferable to operate under an inert gas, e.g.nitrogen, or in vacuo, in the presence or absence of a solvent, such aswater, 1,4-dioxane, dimethylformamide (DMF), or dimethylacetamide(DMAC). Examples of solvent mixtures with good suitability are thosecomposed of water and 1,4-dioxane. However, there is no need to use asolvent; by way of example, the carboxylic acid may be used as initialcharge and melted, and the amine may be added to the melt. The water ofreaction formed during the course of the polymerization(polycondensation) is, by way of example, drawn off in vacuo or isremoved via azeotropic distillation, using suitable solvents, such astoluene.

The pressure is generally non-critical, being from 1 mbar to 100 barabsolute, for example. If no solvent is used, the water of reaction canbe removed in a simple manner by operating in vacuo, e.g., at from 1 to500 mbar.

The reaction time is usually from 5 minutes to 48 hours, preferably from30 minutes to 24 hours, and more preferably from 1 hour to 10 hours.

The reaction of carboxylic acid and amine may take place in the absenceor presence of catalysts. Examples of suitable catalysts are theamidation catalysts mentioned at a later stage below.

If use is also made of catalysts, their amount is usually from 1 to 5000ppm by weight, preferably from 10 to 1000 ppm by weight, based on theentirety of the monomers A₂ and B₃.

During or after the polymerization process, the chain extenders Cmentioned may be added, if desired. For chemical modification of thehyperbranched polyamide it is also possible to add the comonomers Dmentioned, prior to, during, or after the polymerization process.

The reaction of the comonomers D may be catalyzed via conventionalamidation catalysts, if required. Examples of these catalysts areammonium phosphate, triphenyl phosphite, or dicyclohexylcarbodiimide. Inparticular when using heat-sensitive comonomers D, and when usingmethacrylates or fatty alcohols as comonomer D, the reaction may also becatalyzed via enzymes, operations usually being carried out at from 40to 90° C., preferably from 50 to 85° C., and in particular 55 to 80° C.,and in the presence of a free-radical inhibitor.

Free-radical polymerization and also unwanted crosslinking reactions ofunsaturated functional groups are inhibited by the inhibitor and, ifappropriate, by operating under an inert gas. Examples of theseinhibitors are hydroquinone, the monomethyl ether of hydroquinone,phenothiazine, derivatives of phenol, e.g., 2-tert-butyl-4-methylphenol,6-tert-butyl-2,4-dimethylphenol, or N-oxyl compounds, such asN-oxyl-4-hydroxy-2,2,6,6-tetramethylpiperidine (hydroxy-TEMPO),N-oxyl-4-oxo-2,2,6,6-tetramethylpiperidine (TEMPO), in amounts of from50 to 2000 ppm by weight, based on the entirety of the monomers A₂ andB₃.

The preparation is carried out preferably batchwise, or else possiblycontinuously, for example in stirred vessels, tubular reactors, towerreactors, or other conventional reactors, which may have static ordynamic mixers, and conventional apparatus for pressure control andtemperature control and also for operations under an inert gas.

In the case of operation without solvent, the final product is generallyobtained directly and, if necessary, can be purified via conventionalpurification operations. If use has been made of a solvent, it may beremoved in the usual way from the reaction mixture after the reaction,for example via vacuum distillation.

The inventive method features great simplicity. It permits thepreparation of hyperbranched polyamides in a simple one-pot reaction.There is no need for isolation or purification of intermediates orprotective groups for intermediates. The method has economic advantages,because the monomers are commercially available and inexpensive

Hyperbranched Polyesteramides

Suitable hyperbranched polyesteramides can be prepared by reacting acarboxylic acid having at least two carboxyl groups with an aminoalcohol which has at least one amino group and at least two hydroxylgroups.

The process starts from a carboxylic acid having at least two carboxygroups (dicarboxylic acid, tricarboxylic acid or carboxylic acid ofhigher functionality) and from an amino alcohol (alkanolamine) having atleast one amino group and having two hydroxyl groups.

Suitable carboxylic acids usually have from 2 to 4, in particular 2 or 3carboxy groups, and have an alkyl, aryl, or arylalkyl radical havingfrom 1 to 30 C atoms. Carboxylic acids contemplated include all di-,tri-, and tetracarboxylic acids already stated for the hyperbranchedpolyamides, and the derivatives of these acids.

The carboxylic acid used is more preferably succinic acid, glutaricacid, adipic acid, 1,2-, 1,3- or 1,4-cyclohexanedicarboxylic acid,phthalic acid, isophthalic acid, terephthalic acid, or dimethyl estersthereof. Succinic acid and adipic acid are very particularly preferred.

Preferred suitable amino alcohols (alkanolamines) having at least oneamino group and at least two hydroxy groups are dialkanolamines andtrialkanolamines. Examples of dialkanolamines which may be used arethose of the formula 1

where R1, R2, R3 and R4 independently of one another, are hydrogen, C₁₋₆alkyl, C₃₋₁₂ cycloalkyl or C₆₋₁₄ aryl (incl. arylalkyl).

Examples of suitable dialkanolamines are diethanolamine,dipropanolamine, diisopropanolamine, 2-amino-1,3-propanediol,3-amino-1,2-propanediol, 2-amino-1,3-propanediol, dibutanolamine,diisobutanolamine, bis(2-hydroxy-1-butyl)amine,bis(2-hydroxy-1-propyl)amine and dicyclohexanolamine.

Suitable trialkanolamines are those of the formula 2

where R1, R2 and R3 are as defined for formula 1, and l, m and n,independently of one another, are whole numbers from 1 to 12. By way ofexample, tris(hydroxymethyl)aminomethane is suitable.

The amino alcohol used preferably comprises diethanolamine (DEA) anddiisopropanolamine (DIPA).

In one preferred process the carboxylic acid used comprises adicarboxylic acid and the amino alcohol used comprises an alcohol havingone amino group and two hydroxy groups.

The process can also be used to prepare functionalized polyesteramides.For this, use is made of comonomers C as well, and these may be addedprior to, during, or after the reaction of carboxylic acid, aminoalcohol, and, if appropriate, monomer M. This gives a polymer chemicallymodified by the comonomer units and their functional groups.

One preferred embodiment of the process is therefore one wherein, priorto, during, or after the reaction of carboxylic acid, amino alcohol and,if appropriate, monomer M, use is made of a comonomer C as well, givinga modified polyesteramide. The comonomer may comprise one, two, or morethan two functional groups.

Suitable comonomers C are the saturated and unsaturated monocarboxylicacids, including fatty acids, their anhydrides and esters, alcohols,acrylates and also the abovementioned monofunctional orhigher-functionality alcohols (among which are diols and polyols),amines (among which are diamines and triamines), and amino alcohols(alkanolamines), as stated for the hyperbranched polyamides before.

The amount of the comonomers C depends in the usual way on the extent towhich the polymer is to be modified. The amount of the comonomers C isgenerally 0.5% to 40% by weight, preferably 1% to 35% by weight, basedon the entirety of the amino alcohol and carboxylic acid monomers used.

The number of free OH groups in (hydroxyl number of) the finalpolyesteramide product is generally from 10 to 500, preferably from 20to 450, mg KOH per gram of polymer, and can be determined, by way ofexample, via titration to DIN 53240-2.

The number of free COOH groups in (acid number of) the finalpolyesteramide product is generally from 0 to 400, preferably from 0 to200, mg KOH per gram of polymer, and can likewise be determined viatitration to DIN 53240-2.

The reaction of the carboxylic acid with the amino alcohol generallytakes place at an elevated temperature, for example at from 80 to 250°C., in particular at from 90 to 220° C., and particularly preferably atfrom 95 to 180° C. If for purposes of modification the polymer isreacted with comonomers C and catalysts are used for this purpose (see alater stage below), the reaction temperature may be adapted to takeaccount of the catalyst used, operations being generally carried out atfrom 90 to 200° C., preferably from 100 to 190° C., and in particularfrom 110 to 180° C.

Operations are preferably carried out under an inert gas, e.g.,nitrogen, or in vacuo, in the presence or absence of a solvent, such as1,4-dioxane, dimethylformamide (DMF), or dimethylacetamide (DMAc).However, there is no requirement to use a solvent; by way of example,the carboxylic acid may be mixed with the amino alcohol and—ifappropriate in the presence of a catalyst—reacted at an elevatedtemperature. The water of reaction formed in the course of thepolymerization (polycondensation) process is, by way of example, drawnoff in vacuo or removed via azeotropic distillation, using suitablesolvents, such as toluene.

The end of the reaction of carboxylic acid and amino alcohol can oftenbe discerned from a sudden rapid rise in the viscosity of the reactionmixture. When the viscosity begins to rise, the reaction may beterminated, for example by cooling. A specimen of the mixture may thenbe used to determine the number of carboxy groups in the (pre)polymer,for example via titration to give the acid number to DIN 53402-2, andthen, if appropriate, the monomer M and/or comonomer C may be added andreacted.

The pressure is generally not critical and, by way of example, is from 1mbar to 100 bar absolute. If no solvent is used, the water of reactioncan be removed in a simple manner by operating in vacuo, e.g., at from 1to 500 mbar absolute. The reaction time is usually from 5 minutes to 48hours, preferably from 30 minutes to 24 hours, and more preferably from1 hour to 10 hours.

As mentioned, the comonomers C mentioned may be added prior to, during,or after the polymerization process, in order to achieve chemicalmodification of the hyperbranched polyesteramide.

The process may use a catalyst which catalyzes the reaction of thecarboxylic acid with the amino alcohol (esterification).

Suitable catalysts are acidic, preferably inorganic catalysts,organometallic catalysts, or enzymes.

Examples of acidic inorganic catalysts which may be mentioned aresulfuric acid, phosphoric acid, phosphonic acid, hypophosphorous acid,aluminum sulfate hydrate, alum, acidic silica gel (pH≦6, in particular≦5), and acidic aluminum oxide. Other examples of acidic inorganiccatalysts which may be used are aluminum compounds of the generalformula Al(OR)₃ and titanates of the general formula Ti(OR)₄. Examplesof preferred acidic organometallic catalysts are those selected fromdialkyltin oxides R₂SnO, where R is as defined above. One particularlypreferred representative of acidic organometallic catalysts isdi-n-butyltin oxide, commercially available as “oxotin”. An example of asuitable material is Fascat® 4201, a di-n-butyltin oxide from Atofina.

Preferred acidic organic catalysts are acidic organic compounds having,by way of example, phosphate groups, sulfonic acid groups, sulfategroups, or phosphonic acid groups. Particular preference is given tosulfonic acids, such as para-toluenesulfonic acid. It is also possibleto use acidic ion exchangers as acidic organic catalysts, an examplebeing polystyrene resins which contain sulfonic acid groups and whichhave been crosslinked with about 2 mol % of divinylbenzene.

If use is made of a catalyst, its amount is usually from 1 to 5000 ppmby weight, preferably from 10 to 1000 ppm by weight, based on theentirety of carboxylic acid and amino alcohol.

Specifically, the reaction of the comonomers C can also be catalyzed viaconventional amidation catalysts, usually operating at from 40 to 90°C., preferably from 50 to 85° C., and in particular from 55 to 80° C.,and in the presence of a free-radical inhibitor.

The inventive process may preferably be carried out batchwise, or elsecontinuously, for example in stirred vessels, tubular reactors, towerreactors, or other conventional reactors, which may have static ordynamic mixers and conventional apparatus for pressure control andtemperature control and also for operations under an inert gas.

In the case of operation without solvent, the final product is generallyobtained directly and, if necessary, can be purified via conventionalpurification operations. If concomitant use has been made of a solvent,this may be removed in the usual way from the reaction mixture after thereaction, for example via vacuum distillation.

The hyperbranched polymers described above may additionally be subjectedto polymer-analogous reaction. In this way it is possible to adapt theirproperties even more effectively, in certain circumstances, to their usein various dispersions. For polymer-analogous reaction it is possible tosubject functional groups originally present in the polymer (e.g., A orB groups) to reaction, such that the resulting polymers contain at leastone new functionality.

The polymer-analogous reaction of the hyperbranched polymers may takeplace during the preparation of the polymers, immediately after thepolymerization reaction, or in a separate reaction step.

If, before or during polymer synthesis, components are added that aswell as A and B groups contain further functional groups, the product isa hyperbranched polymer in which these further functional groups aredistributed substantially at random.

Compounds used for the transfunctionalization may comprise firstly thedesired functional group for new introduction, and also a second groupthat is capable of reacting with the B groups of the hyperbranchedpolymer starting material used, to form a bond. One example of this isthe reaction of an isocyanate group with a hydroxycarboxylic acid orwith an aminocarboxylic acid, to form an acid functionality, or thereaction of an OH group with acrylic anhydride, to form a reactiveacrylic double bond.

Examples of suitable functional groups that can be introduced by meansof suitable reaction partners comprise, in particular, acidic or basicgroups containing H atoms, and the derivatives of such groups, such as—OC(O)OR, —COOH, —COOR, —CONHR, —CONH₂, —OH, —SH, —NH₂, —NHR, —NR₂,—SO₃H, —SO₃R, —NHCOOR, —NHCONH₂, —NHCONHR, etc. If appropriate it isalso possible to convert ionizable functional groups into thecorresponding salts by means of suitable acids or bases. A furtherpossibility is to subject primary, secondary or tertiary amino groups toquaternization, with alkyl halides or dialkyl sulfates, for example.This procedure can be used, for example, to obtain water-soluble orwater-dispersible hyperbranched polymers.

The radicals R of said groups are preferably straight-chain or branched,unsubstituted or substituted, alkyl radicals. For example they areC₁-C₃₀ alkyl radicals or C₆-C₁₄ aryl radicals. Examples of suitablefunctional groups are —CN or —OR^(a), with R^(a)═H or alkyl.

For the use of the hyperbranched polymers in dispersions it may beadvantageous for hydrophilic and hydrophobic moieties to have aparticular proportion to one another. Hydrophobicization of ahyperbranched polymer can be accomplished, for example, by usingmonofunctional hydrophobic compounds, with which reactive groups presentare modified before, during or after the polymerization. Thus, forexample, the polymers of the invention can be hydrophobicized byreaction with monofunctional, saturated or unsaturated aliphatic oraromatic amines, alcohols, carboxylic acids, epoxides or isocyanates.

Additionally it is also possible, for example, to incorporatedifunctional or higher polyfunctional monomers containing hydrophobicgroups by copolymerization during the molecular weight build-up. Forthis purpose it is possible, for example, to use difunctional or higherpolyfunctional alcohols, amines, isocyanates, carboxylic acids and/orepoxides, which in addition to the reactive groups also carry aromaticradicals or long-chain alkane, alkene or akyne radicals.

Examples of monomers of this kind are alcohols, such as glycerolmonostearate, glycerol monooleate, hexanediol, octanediol, decanediol,dodecanediol, octadecanediol, dimer fatty alcohos, amines, such ashexamethylenediamine, octanediamine, dodecanediamine, isocyanates, suchas aromatic or aliphatic di- and polyisocyanates, e.g., diphenylmethanediisocyanate and its higher-oligomer species, tolylene diisocyanate,naphthylene diisocyanate, xylylene diisocyanate, hexamethylenediisocyanate, hexamethylene diisocyanate trimers, isophoronediisocyanate, bis(diisocyanatocyclohexyl)methane orbis(isocyanatomethyl)cyclohexane, and acids, such as adipic acid,octanedioic acid, dodecanedioic acids, octadecanedioic acid or dimerfatty acids.

The hyperbranched polymers used in accordance with the invention mayalso be hydrophilicized. This can be done, for example, by convertinghyperbranched polymers comprising hydroxyl groups and/or primary orsecondary amino groups into high-functionality polymer polyols byreaction with alkylene oxides, such as ethylene oxide, propylene oxide,butylene oxide or mixtures thereof. For the alkoxylation it is preferredto use ethylene oxide. As a further option, however, alkylene oxidealcohols or alkylene oxide amines with a functionality of two or morecan be used as synthesis components during the preparation of thehyperbranched polymers.

It is also possible to generate hyperbranched polymers which havedifferent functionalities. This can be accomplished, for example,through reaction with a mixture of different compounds for thetransfunctionalization, or else by reacting only some of the functionalgroups originally present.

It is further possible to generate compounds of mixed functionality byusing monomers of type ABC or AB₂C for the polymerization, Crepresenting a functional group which is not reactive with A or B underthe chosen reaction conditions.

Polymer Dispersion PD)

The polymer dispersion PD) is prepared using at least one ethylenicallyunsaturated monomer (M). The monomer (M) comprises α,β-ethylenicallyunsaturated monomers, which for the purpose of the invention comprehendsmonomers having a terminal double bond. The monomer (M) is preferablyselected from esters of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with C₁-C₂₀ alkanols, vinylaromatics, esters of vinylalcohol with C₁-C₃₀ monocarboxylic acids, ethylenically unsaturatednitriles, vinyl halides, vinylidene halides, monoethylenicallyunsaturated carboxylic and sulfonic acids, phosphorus monomers, estersof α,β-ethylenically unsaturated monocarboxylic and dicarboxylic acidswith C₂-C₃₀ alkanediols, amides of α,β-ethylenically unsaturatedmonocarboxylic and dicarboxylic acids with C₂-C₃₀ amino alcohols whichcontain a primary or secondary amino group, primary amides ofα,β-ethylenically unsaturated monocarboxylic acids and their N-alkyl andN,N-dialkyl derivatives, N-vinyllactams, open-chain N-vinylamidecompounds, esters of allyl alcohol with C₁-C₃₀ monocarboxylic acids,esters of α,β-ethylenically unsaturated monocarboxylic and dicarboxylicacids with amino alcohols, amides of α,β-ethylenically unsaturatedmonocarboxylic and dicarboxylic acids with diamines which contain atleast one primary or secondary amino group, N,N-diallylamines,N,N-diallyl-N-alkylamines, vinyl- and allyl-substituted nitrogenheterocycles, vinyl ethers, C₂-C₈-monoolefins, nonaromatic hydrocarbonshaving at least two conjugated double bonds, polyether (meth)acrylates,monomers containing urea groups, and mixtures thereof.

Suitable esters of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with C₁-C₂₀ alkanols are methyl(meth)acrylate, methylethacrylate, ethyl (meth)acrylate, ethyl ethacrylate, n-propyl(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, tert-butylethacrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl(meth)acrylate, 1,1,3,3-tetramethylbutyl (meth)acrylate, ethylhexyl(meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate,n-undecyl (meth)acrylate, tridecyl (meth)acrylate, myristyl(meth)acrylate, pentadecyl (meth)acrylate, palmityl (meth)acrylate,heptadecyl (meth)acrylate, nonadecyl (meth)acrylate, arachinyl(meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate,cerotinyl (meth)acrylate, melissinyl (meth)acrylate, palmitoleyl(meth)acrylate, oleyl (meth)acrylate, linolyl (meth)acrylate, linolenyl(meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, andmixtures thereof.

Preferred vinylaromatics are styrene, 2-methylstyrene, 4-methylstyrene,2-(n-butyl)styrene, 4-(n-butyl)styrene, 4-(n-decyl)styrene, and, withparticular preference, styrene.

Suitable esters of vinyl alcohol with C₁-C₃₀ monocarboxylic acids are,for example, vinyl formate, vinyl acetate, vinyl propionate, vinylbutyrate, vinyl laurate, vinyl stearate, vinyl propionate, versatic acidvinyl esters, and mixtures thereof.

Suitable ethylenically unsaturated nitriles are acrylonitrile,methacrylonitrile, and mixtures thereof.

Suitable vinyl halides and vinylidene halides are vinyl chloride,vinylidene chloride, vinyl fluoride, vinylidene fluoride, and mixturesthereof.

Suitable ethylenically unsaturated carboxylic acids, sulfonic acids, andphosphonic acids or their derivatives are acrylic acid, methacrylicacid, ethacrylic acid, α-chloroacrylic acid, crotonic acid, maleic acid,maleic anhydride, itaconic acid, citraconic acid, mesaconic acid,glutaconic acid, aconitic acid, fumaric acid, the monoesters ofmonoethylenically unsaturated dicarboxylic acids having 4 to 10,preferably 4 to 6, C atoms, e.g., monomethyl maleate, vinylsulfonicacid, allylsulfonic acid, sulfoethyl acrylate, sulfoethyl methacrylate,sulfopropyl acrylate, sulfopropyl methacrylate,2-hydroxy-3-acryloyloxypropylsulfonic acid,2-hydroxy-3-methacryloyloxypropylsulfonic acid, styrenesulfonic acids,and 2-acrylamido-2-methylpropanesulfonic acid. Suitable styrenesulfonicacids and derivates thereof are styrene-4-sulfonic acid andstyrene-3-sulfonic acids and the alkali metal or alkaline earth metalsalts thereof, such as sodium styrene-3-sulfonate and sodiumstyrene-4-sulfonate, for example. Particularly preferred are acrylicacid, methacrylic acid, and mixtures thereof.

Examples of phosphorous monomers are vinylphosphonic acid andallylphosphonic acid, for example. Also suitable are the monoesters anddiesters of phosphonic acid and phosphoric acid with hydroxyalkyl(meth)acrylates, especially the monoesters. Additionally suitable arediesters of phosphonic acid and phosphoric acid that have beenesterified once with hydroxyalkyl (meth)acrylate and also once with adifferent alcohol, such as an alkanol, for example. Suitablehydroxyalkyl (meth)acrylates for these esters are those specified belowas separate monomers, more particularly 2-hydroxyethyl(meth)acrylate,3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.Corresponding dihydrogen phosphate ester monomers comprise phosphoalkyl(meth)acrylates, such as 2-phosphoethyl (meth)acrylate, 2-phosphopropyl(meth)acrylate, 3-phosphopropyl (meth)acrylate, phosphobutyl(meth)acrylate, and 3-phospho-2-hydroxypropyl (meth)acrylate. Alsosuitable are the esters of phosphonic acid and phosphoric acid withalkoxylated hydroxyalkyl (meth)acrylates, examples being the ethyleneoxide condensates of (meth)acrylates, such asH₂C═C(H,CH₃)COO(CH₂CH₂O)_(n)P(OH)₂ andH₂C═C(H,CH₃)COO(CH₂CH₂O)_(n)P(═O)(OH)₂, in which n is 1 to 50. Offurther suitability are phosphoalkyl crotonates, phosphoalkyl maleates,phosphoalkyl fumarates, phosphodialkyl (meth)acrylates, phosphodialkylcrotonates and allyl phosphates. Further suitable monomers containingphosphorus groups are described in WO 99/25780 and U.S. Pat. No.4,733,005, hereby incorporated by reference.

Suitable esters of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with C₂-C₃₀ alkanediols are, for example,2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethylethacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutylacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate,4-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexylmethacrylate, 3-hydroxy-2-ethylhexyl acrylate, 3-hydroxy-2-ethylhexylmethacrylate, etc.

Suitable primary amides of α,β-ethylenically unsaturated monocarboxylicacids and their N alkyl and N,N-dialkyl derivatives are acrylamide,methacrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide,N-propyl(meth)acrylamide, N-(n-butyl)(meth)acrylamide,N-(tert-butyl)(meth)acrylamide, N-(n-octyl)(meth)acrylamide,N-(1,1,3,3-tetramethylbutyl)(meth)acrylamide,N-ethylhexyl(meth)acrylamide, N-(n-nonyl)(meth)acrylamide,N-(n-decyl)(meth)acrylamide, N-(n-undecyl)(meth)acrylamide,N-tridecyl(meth)acrylamide, N-myristyl(meth)acrylamide,N-pentadecyl(meth)acrylamide, N-palmityl(meth)acrylamide,N-heptadecyl(meth)acrylamide, N-nonadecyl(meth)acrylamide,N-araquinyl(meth)acrylamide, N-behenyl(meth)acrylamide,N-lignoceryl(meth)acrylamide, N-cerotinyl(meth)acrylamide,N-melissinyl(meth)acrylamide, N-palmitoleyl(meth)acrylamide,N-oleyl(meth)acrylamide, N-linolyl(meth)acrylamide,N-linolenyl(meth)acrylamide, N-stearyl(meth)acrylamide,N-lauryl(meth)acrylamide, N,N-dimethyl(meth)acrylamide,N,N-diethyl(meth)acrylamide, morpholinyl(meth)acrylamide.

Suitable N-vinyllactams and their derivatives are, for example,N-vinylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam,N-vinyl-5-methyl-2-pyrrolidone, N-vinyl-5-ethyl-2-pyrrolidone,N-vinyl-6-methyl-2-piperidone, N-vinyl-6-ethyl-2-piperidone,N-vinyl-7-methyl-2-caprolactam, N-vinyl-7-ethyl-2-caprolactam, etc.

Suitable open-chain N-vinylamide compounds are, for example,N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide,N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide,N-vinylpropionamide, N-vinyl-N-methylpropionamide and N-vinylbutyramide.

Suitable esters of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with amino alcohols areN,N-dimethylaminomethyl(meth)acrylate,N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethylacrylate,N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl(meth)acrylate and N,N-dimethylaminocyclohexyl (meth)acrylate.

Suitable amides of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with diamines which contain at least one primary orsecondary amino group are N-[2-(dimethylamino)ethyl]acrylamide,N-[2-(dimethylamino)ethyl]methacrylamide,N-[3-(dimethylamino)propyl]acrylamide,N-[3-(dimethylamino)propyl]methacrylamide,N-[4-(dimethylamino)butyl]acrylamide,N-[4-(dimethylamino)-butyl]methacrylamide,N-[2-(diethylamino)ethyl]acrylamide,N-[4-(dimethylamino)cyclohexyl]acrylamide,N-[4-(dimethylamino)cyclohexyl]methacrylamide, etc.

Suitable monomers M) are, furthermore, N,N-diallylamines andN,N-diallyl-N-alkylamines and their acid addition salts andquaternization products. Alkyl here is preferably C₁-C₂₄ alkyl.Preference is given to N,N-diallyl-N-methylamine and toN,N-diallyl-N,N-dimethylammonium compounds, such as the chlorides andbromides, for example.

Further suitable monomers M) are vinyl- and allyl-substituted nitrogenheterocycles, such as N-vinylimidazole, N-vinyl-2-methylimidazole, andvinyl- and allyl-substituted heteroaromatic compounds, such as 2- and4-vinylpyridine, 2- and 4-allylpyridine, and the salts thereof.

Suitable C₂-C₈ monoolefins and nonaromatic hydrocarbons having at leasttwo conjugated double bonds are ethylene, propylene, isobutylene,isoprene, butadiene, etc.

Suitable polyether (meth)acrylates are compounds of the general formula(A)

in which

-   the sequence of the alkylene oxide units is arbitrary,-   k and l independently of one another are an integer from 0 to 100,    the sum of k and l being at least 3,-   R^(a) is hydrogen, C₁-C₃₀ alkyl, C₅-C₈ cycloalkyl, C₆-C₁₄-aryl or    (C₆-C₁₄-)aryl-(C₁-C₄-)alkyl,-   R^(b) is hydrogen or C₁-C₈ alkyl,-   Y is O or NR^(c), where R^(c) is hydrogen, C₁-C₃₀ alkyl or C₅-C₈    cycloalkyl.

Preferably k is an integer from 1 to 100, more preferably from 3 to 50,more particularly 4 to 25. Preferably l is an integer from 0 to 100,more preferably from 3 to 50, more particularly 4 to 25.

The sum of k and l is preferably from 3 to 200, more particularly from 4to 100.

Preferably R^(a) in the formula (A) is hydrogen or C₁-C₁₈-alkyl, such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-pentyl,n-hexyl, octyl, 2-ethylhexyl, decyl, lauryl, palmityl or stearyl.

Preferably R^(b) is hydrogen or C₁-C₆-alkyl, such as methyl, ethyl,n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl orn-hexyl, more particularly hydrogen, methyl or ethyl. With particularpreference R^(b) is hydrogen or methyl.

Preferably Y in the formula (A) is O or NH, especially O.

Examples of suitable polyether (meth)acrylates are the polycondensationproducts of the aforementioned α,β-ethylenically unsaturatedmonocarboxylic and/or dicarboxylic acids and their acid chlorides, acidamides, and acid anhydrides with polyetherols. Suitable polyetherols arereadily preparable by reaction of ethylene oxide, 1,2-propylene oxideand/or epichlorohydrin with a starter molecule, such as water orshort-chain alcohol R^(a)—OH. The alkylene oxides can be usedindividually, in alternation in succession or as a mixture. Thepolyether acrylates can be used alone or in mixtures for preparing theemulsion polymers employed in accordance with the invention.

The polymer dispersion PD) preferably comprises in copolymerized form atleast one polyether (meth)acrylate selected from the compounds of thegeneral formulae I or II or mixtures thereof

in which

-   n is an integer from 3 to 15, preferably 4 to 12,-   R^(a) is hydrogen, C₁-C₂₀ alkyl, C₅-C₈ cycloalkyl or C₆-C₁₄ aryl,-   R^(b) is hydrogen or methyl.

Suitable polyether (meth)acrylates are available commercially, in theform for example of various products designated Bisomer® from LaportePerformance Chemicals, UK. They include, for example, Bisomer MPEG 350MA, a methoxypolyethylene glycol monomethacrylate.

Examples of suitable monomers containing urea groups are N-vinylurea orN-allylurea or derivatives of imidazolidin-2-one. They include N-vinyl-and N-allylimidazolidin-2-one, N-vinyl oxyethylimidazolidin-2-one,N-(2-(meth)acrylamidoethyl)imidazolidin-2-one,N-(2-(meth)acryloxyethyl)imidazolidin-2-one (i.e., 2-ureido(meth)acrylate), N-[2-((meth)acryloxyacetamido)ethyl]imidazolidin-2-one,etc.

Preferred monomers containing urea groups areN-(2-acryloxyethyl)imidazolidin-2-one andN-(2-methacryloxyethyl)imidazolidin-2-one. Particular preference isgiven to N-(2-methacryloxyethyl)imidazolidin-2-one(2-ureidomethacrylate, UMA).

The aforementioned monomers M) may be used individually, in the form ofmixtures within one class of monomer, or in the form of mixtures fromdifferent classes of monomer.

For the emulsion polymerization it is preferred to use at least 40%,more preferably at least 60%, and more particularly at least 80% byweight, based on the total weight of the monomers M), and at least onemonomer M1) selected from esters of α,β-ethylenically unsaturatedmonocarboxylic and dicarboxylic acids with C₁-C₂₀ alkanols,vinylaromatics, esters of vinyl alcohol with C₁-C₃₀ monocarboxylicacids, ethylenically unsaturated nitriles, vinyl halides, vinylidenehalides, and mixtures thereof (principal monomers). Preferably themonomers M1) are used for the emulsion polymerization in an amount of upto 99.9%, more preferably up to 99.5%, more particularly up to 99%, byweight, based on the total weight of the monomers M).

The principal monomers M1) are preferably selected frommethyl(meth)acrylate, ethyl(meth)acrylate, n-propyl (meth)acrylate,isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl(meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate,n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate,2-ethylhexyl (meth)acrylate, styrene, 2-methylstyrene, vinyl acetate,acrylonitrile, methacrylonitrile, and mixtures thereof.

In addition to at least one principal monomer M1) it is also possible inthe free-radical emulsion polymerization for the preparation of PD) touse at least one further monomer M2), which is generally present in aminority amount (secondary monomers). For the emulsion polymerization itis preferred to use up to 60%, more preferably up to 40%, and moreparticularly up to 20% by weight, based on the total weight of themonomers M), of at least one monomer M2) selected from ethylenicallyunsaturated monocarboxylic and dicarboxylic acids and the anhydrides andmonoesters of ethylenically unsaturated dicarboxylic acids,ethylenically unsaturated sulfonic acids, (meth)acrylamides, C₁-C₁₀hydroxyalkyl (meth)acrylates, C₁-C₁₀ hydroxyalkyl(meth)acrylamides, andmixtures thereof. Preferably the monomers M2), when present, are usedfor the emulsion polymerization in an amount of at least 0.01%, morepreferably at least 0.05% by weight, more particularly at least 0.1%, byweight, especially at least 0.5% by weight, more especially at least 1%by weight, based on the total weight of the monomers M).

For the emulsion polymerization it is particularly preferred to use 0.1%to 60%, preferably 0.5% to 40%, more particularly 1% to 20% by weight ofat least one monomer M2). The monomers M2) in a first version compriseat least one monomer which carries acid groups and is preferablyselected from monoethylenically unsaturated C₃-C₈ monocarboxylic acids,monoethylenically unsaturated C₄-C₈ dicarboxylic acids, their anhydridesand monoesters, monoethylenically unsaturated sulfonic acids andmixtures thereof. The fraction of monomers M2) which carry acid groups(if such monomers are present) is preferably 0.05% to 15% by weight,more preferably 0.1% to 10% by weight, based on the total weight of themonomers M). In a second version the monomers M2) comprise at least oneneutral, monoethylenically unsaturated monomer which is preferablyselected from amides of monoethylenically unsaturated C₃-C₈monocarboxylic acids, hydroxy-C₂-C₄ alkyl esters of monoethylenicallyunsaturated C₃-C₈ monocarboxylic acids, and mixtures thereof. Thefraction of neutral monomers M2) (if such monomers are present) ispreferably 0.01% to 15% by weight, more preferably 0.1% to 10% byweight, based on the total weight of the monomers M). In a thirdversion, the monomers M2) comprise a mixture of at least one monomerwhich carries acid groups and at least one neutral, monoethylenicallyunsaturated monomer. The sum of these monomers M2) is preferably 0.1% to20% by weight, more preferably 0.5% to 15% by weight, based on the totalweight of the monomers M). The monomers M2) are especially selected fromacrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaricacid, maleic anhydride, acrylamide, methacrylamide, 2-hydroxyethylacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethylacrylamide,2-hydroxyethylmethacrylamide, and mixtures thereof.

Examples of particularly suitable combinations of principal monomers M1)for the methods of the invention are as follows:

-   n-butyl acrylate, methyl methacrylate;-   n-butyl acrylate, methylmethacrylate, styrene;-   n-butyl acrylate, styrene;-   n-butyl acrylate, ethylhexyl acrylate;-   n-butyl acrylate, ethylhexyl acrylate, styrene.

The aforementioned particularly suitable combinations of principalmonomers M1) can be combined with particularly suitable monomers M2),which are preferably selected from acrylic acid, methacrylic acid,acrylamide, methacrylamide, and mixtures thereof.

In one specific embodiment the free-radical emulsion polymerization forthe preparation of PD) is carried out using at least one polyether(meth)acrylate in addition to M1) and, if present, M2). This polyether(meth)acrylate is used preferably in an amount of up to 25% by weight,more preferably up to 20% by weight, based on the total weight of themonomers M). For the emulsion polymerization it is particularlypreferred to use 0.1% to 20% by weight, preferably 1% to 15% by weight,of at least one polyether (meth)acrylate. Suitable polyether(meth)acrylates are those mentioned above. Preferably the polyether(meth)acrylate is selected from compounds of the general formulae I orII or mixtures thereof

in which

-   n is an integer from 3 to 15, preferably 4 to 12,-   R^(a) is hydrogen, C₁-C₂₀ alkyl, C₅-C₈ cycloalkyl or C₆-C₁₄ aryl,-   R^(b) is hydrogen or methyl.

In one specific embodiment the free-radical emulsion polymerization forthe preparation of PD) is carried out using at least one monomercontaining urea groups, in addition to M1) and, if present, M2) and/orpolyether (meth)acrylates. This urea-functional monomer is usedpreferably in an amount of up to 25% by weight, more preferably up to20% by weight, based on the total weight of the monomers M). For theemulsion polymerization it is particularly preferred to use 0.1% up to20% by weight, more particularly 1% to 15% by weight, of at least onemonomer containing urea groups. Suitable monomers containing urea groupsare those specified above. In the preparation of the polymer dispersionsof the invention it is possible to use at least one crosslinker inaddition to the aforementioned monomers M). Monomers which possess acrosslinking function are compounds having at least two polymerizable,ethylenically unsaturated, nonconjugated double bonds in the molecule.Crosslinking may also take place, for example, through photochemicalactivation. For that purpose it is possible to prepare PD) additionallyusing at least one monomer containing photoactivable groups.Photoinitiators can also be added separately. Crosslinking can also beaccomplished, for example, by means of functional groups which are ableto enter into a chemical crosslinking reaction with complementaryfunctional groups. In that case the complementary groups may both beattached to the emulsion polymer. For the crosslinking it is possible touse a crosslinker which is capable of being able to enter into achemical crosslinking reaction with functional groups of the emulsionpolymer.

Suitable crosslinkers are, for example, acrylic esters, methacrylicesters, allyl ethers or vinyl ethers of at least dihydric alcohols. TheOH groups of the parent alcohols may be wholly or partly etherified oresterified; the crosslinkers, however, comprise at least twoethylenically unsaturated groups.

Examples of the parent alcohols are dihydric alcohols such as1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol,1,3-butanediol, 2,3-butanediol, 1,4-butanediol, but-2-ene-1,4-diol,1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol,1,10-decanediol, 1,2-dodecanediol, 1,12-dodecanediol, neopentyl glycol,3-methylpentane-1,5-diol, 2,5-dimethyl-1,3-hexanediol,2,2,4-trimethyl-1,3-pentanediol, 1,2-cyclohexanediol,1,4-cyclohexanediol, 1,4-bis(hydroxymethyl)cyclohexane, hydroxypivalicacid neopentyl glycol monoester, 2,2-bis(4-hydroxyphenyl)propane,2,2-bis[4-(2-hydroxypropyl)phenyl]propane, diethylene glycol,triethylene glycol, tetraethylene glycol, dipropylene glycol,tripropylene glycol, tetrapropylene glycol, 3-thiapentane-1,5-diol, andalso polyethylene glycols, polypropylene glycols, andpolytetrahydrofurans having molecular weights of in each case 200 to 10000. Besides the homopolymers of ethylene oxide or propylene oxide it isalso possible to use block copolymers of ethylene oxide or propyleneoxide, or copolymers which incorporate ethylene oxide and propyleneoxide groups. Examples of parent alcohols having more than two OH groupsare trimethylolpropane, glycerol, pentaerythritol, 1,2,5-pentanetriol,1,2,6-hexanetriol, cyanuric acid, sorbitan, sugars such as sucrose,glucose, and mannose. The polyhydric alcohols can of course also beused, following reaction with ethylene oxide or propylene oxide, in theform of the corresponding ethoxylates or propoxylates. The polyhydricalcohols can also first be converted to the corresponding glycidylethers by reaction with epichlorohydrin.

Additional suitable crosslinkers are the vinyl esters or the esters ofmonohydric, unsaturated alcohols with ethylenically unsaturated C₃-C₆carboxylic acids, examples being acrylic acid, methacrylic acid,itaconic acid, maleic acid or fumaric acid. Examples of such alcoholsare allyl alcohol, 1-buten-3-ol, 5-hexen-1-ol, 1-octen-3-ol,9-decen-1-ol, dicyclopentenyl alcohol, 10-undecen-1-ol, cinnamylalcohol, citronellol, crotyl alcohol or cis-9-octadecen-1-ol. Analternative option is to esterify the monohydric, unsaturated alcoholswith polybasic carboxylic acids, examples being malonic acid, tartaricacid, trimellitic acid, phthalic acid, terephthalic acid, citric acid orsuccinic acid.

Other suitable crosslinkers are esters of unsaturated carboxylic acidswith the above-described polyhydric alcohols, examples being those ofoleic acid, crotonic acid, cinnamic acid or 10-undecenoic acid.

Suitable crosslinkers, furthermore, are straight-chain or branched,linear or cyclic, aliphatic or aromatic hydrocarbons which possess atleast two double bonds, which in the case of aliphatic hydrocarbons mustnot be conjugated, examples being divinylbenzene, divinyltoluene,1,7-octadiene, 1,9-decadiene, 4-vinyl-1-cyclohexene, trivinylcyclohexaneor polybutadienes having molecular weights of 200 to 20 000.

Further suitable crosslinkers are the acrylamides, methacrylamides, andN-allylamines of at least difunctional amines. Such amines are, forexample, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane,1,6-diaminohexane, 1,12-dodecanediamine, piperazine, diethylenetriamineor isophoronediamine. Likewise suitable are the amides formed fromallylamine and unsaturated carboxylic acids, such as acrylic acid,methacrylic acid, itaconic acid, maleic acid, or at least dibasiccarboxylic acids, of the kind described above.

Furthermore, triallylamine and triallylmonoalkylammonium salts, e.g.,triallylmethylammonium chloride or triallylmethylammonium methylsulfate,are suitable as crosslinkers.

Also suitable are N-vinyl compounds of urea derivatives, at leastdifunctional amides, cyanurates or urethanes, such as of urea,ethyleneurea, propyleneurea or tartaramide, for example, such asN,N′-divinylethyleneurea or N,N′-divinylpropyleneurea.

Further suitable crosslinkers are divinyldioxane, tetraallylsilane ortetravinylsilane. It will be appreciated that mixtures of theaforementioned compounds can also be used. Preference is given to usingwater-soluble crosslinkers.

Further included among the crosslinking monomers are those which as wellas an ethylenically unsaturated double bond contain a reactivefunctional group, such as an aldehyde group, a keto group or an oxiranegroup, able to react with an added crosslinker. The functional groupsare preferably keto groups or aldehyde groups. The keto or aldehydegroups are preferably attached to the polymer through copolymerizationof copolymerizable, ethylenically unsaturated compounds with keto oraldehyde groups. Suitable such compounds are acrolein, methacrolein,vinyl alkyl ketones having 1 to 20, preferably 1 to 10, carbon atoms inthe alkyl radical, formylstyrene, (meth)acrylic acid alkyl esters havingone or two keto or aldehyde groups or one aldehyde group and one ketogroup in the alkyl radical, the alkyl radical preferably comprising atotal of 3 to 10 carbon atoms, examples being(meth)acryloxyalkylpropanals, as described in DE-A-2722097. Alsosuitable, furthermore, are N-oxoalkyl(meth)acrylamides of the kindknown, for example, from U.S. Pat. No. 4,226,007, DE-A-2061213 orDE-A-2207209. Particularly preferred are acetoacetyl (meth)acrylate,acetoacetoxyethyl(meth)acrylate and, more particularly,diacetoneacrylamide. The crosslinkers are preferably a compound with atleast two functional groups, more particularly two to five functionalgroups, which are able to enter into a crosslinking reaction with thefunctional groups of the polymer, especially the keto or aldehydegroups. Functional groups for the crosslinking of the keto or aldehydegroups include, for example, hydrazide, hydroxylamine or oxime ether oramino groups. Suitable compounds of hydrazide groups are, for example,polycarboxylic hydrazides having a molar weight of up to 500 g/mol.Particularly preferred hydrazide compounds are dicarboxylic dihydrazideshaving preferably 2 to 10 C atoms. Examples of such include oxalicdihydrazide, malonic dihydrazide, succinic dihydrazide, glutaricdihydrazide, adipic dihydrazide, sebacic dihydrazide, maleicdihydrazide, fumaric dihydrazide, itaconic dihydrazide and/orisophthalic dihydrazide. Of particular interest are the following:adipic dihydrazide, sebacic dihydrazide, and isophthalic dihydrazide.Suitable compounds with hydroxylamine or oxime ether groups arespecified for example in WO 93/25588.

By appropriate additization of the aqueous polymer dispersion PD) it isalso possible additionally to produce surface crosslinking. Suchadditization includes, for example, the addition of a photoinitiator, orof siccatives. Suitable photoinitiators are those which are excited bysunlight, examples being benzophenone or derivatives thereof. Suitablesiccatives are the metal compounds recommended for aqueous alkyd resins,based for example on Co or Mn (overview in U. Poth, Polyester andAlkydharze, Vincentz Network 2005, p. 183 f).

The crosslinking component is used preferably in an amount of 0.0005% to5%, more preferably 0.001% to 2.5%, more particularly 0.01% to 1.5%, byweight, based on the total weight of the monomers used for thepolymerization (including the crosslinker).

In one special version the emulsion polymerization is carried out usingat least 98% by weight, more preferably at least 99% by weight, moreparticularly at least 99.5% by weight, especially 100% by weight, ofmonoethylenically unsaturated compounds, based on the total weight ofthe compounds capable of polymerization.

One specific embodiment are polymer dispersions PD) which comprise nocopolymerized crosslinker.

The free-radical polymerization of the monomer mixture M) may take placein the presence of at least one regulator. Regulators are usedpreferably in an amount of 0.0005% to 5%, more preferably of 0.001% to2.5%, and more particularly of 0.01% to 1.5% by weight, based on thetotal weight of the monomers used for the polymerization.

Regulators (polymerization regulators) is a general term for compoundshaving high transfer constants. Regulators accelerate chain transferreactions to bring about reduction in the degree of polymerization ofthe resultant polymers without affecting the overall reaction rate.Regulators may be subdivided into monofunctional, difunctional orpolyfunctional regulators, depending on the number of functional groupsin the molecule that are able to lead to one or more chain transferreactions. Suitable regulators are described comprehensively, forexample, by K. C. Berger and G. Brandrup in J. Brandrup, E. H. Immergut,Polymer Handbook, 3^(rd) ed., John Wiley & Sons, New York, 1989, p.II/81-II/141.

Examples of suitable regulators include aldehydes such as formaldehyde,acetaldehyde, propionaldehyde, n-butyraldehyde, and isobutyraldehyde.

Other regulators which can also be used are as follows: formic acid, itssalts or esters, such as ammonium formate, 2,5-diphenyl-1-hexene,hydroxylammonium sulfate, and hydroxylammonium phosphate.

Further suitable regulators are halogen compounds, examples being alkylhalides such as tetrachloromethane, chloroform, bromotrichloromethane,bromoform, allyl bromide, and benzyl compounds such as benzyl chlorideor benzyl bromide.

Further suitable regulators are allyl compounds, such as allyl alcohol,functionalized allyl ethers, such as allyl ethoxylates, alkyl allylethers or glycerol monoallyl ether.

As regulators it is preferred to use compounds comprising sulfur inbound form.

Examples of compounds of this kind are inorganic hydrogen sulfites,disulfites, and dithionites or organic sulfides, disulfides,polysulfides, sulfoxides, and sulfones. They include di-n-butyl sulfide,di-n-octyl sulfide, diphenyl sulfide, thiodiglycol, ethylthio-ethanol,diisopropyl disulfide, di-n-butyl disulfide, di-n-hexyl disulfide,diacetyl disulfide, diethanol sulfide, di-tert-butyl trisulfide,dimethyl sulfoxide, dialkyl sulfide, dialkyl disulfide and/or diarylsulfide.

Suitable polymerization regulators further include thiols (compoundswhich acquire sulfur in the form of SH groups, also referred to asmercaptans). Preferred regulators are mono-, di-, and polyfunctionalmercaptans, mercapto alcohols and/or mercapto carboxylic acids. Examplesof these compounds are allyl thioglycolates, ethyl thioglycolate,cysteine, 2-mercaptoethanol, 1,3-mercaptopropanol,3-mercaptopropane-1,2-diol, 1,4-mercaptobutanol, mercaptoacetic acid,3-mercaptopropionic acid, mercaptosuccinic acid, thioglycerol,thioacetic acid, thiourea, and alkyl mercaptans such as n-butylmercaptan, n-hexyl mercaptan or n-dodecylmercaptan.

Examples of difunctional regulators, comprising two sulfur atoms inbound form, are difunctional thiols such as, for example,dimercaptopropanesulfonic acid (sodium salt), dimercaptosuccinic acid,dimercapto-1-propanol, dimercaptoethane, dimercaptopropane,dimercaptobutane, dimercaptopentane, dimercaptohexane, ethylene glycolbisthioglycolates and butanediol bisthioglycolate. Examples ofpolyfunctional regulators are compounds which comprise more than twosulfur atoms in bound form. Examples thereof are trifunctional andtetrafunctional mercaptans.

All of the stated regulators may be used individually or in combinationwith one another. One specific embodiment relates to polymer dispersionsPD which are prepared by free-radical emulsion polymerization with theaddition of a regulator.

To prepare the polymers it is possible to polymerize the monomers withthe aid of initiators that form free radicals.

As initiators for the free-radical polymerization it is possible toemploy the peroxo and/or azo compounds customary for the purpose,examples being alkali metal or ammonium peroxidisulfates, diacetylperoxide, dibenzoyl peroxide, succinyl peroxide, di-tert-butyl peroxide,tert-butyl perbenzoate, tert-butyl perpivalate, tert-butylperoxy-2-ethylhexanoate, tert-butyl permaleate, cumene hydroperoxide,diisopropyl peroxidicarbamate, bis(o-toluoyl) peroxide, didecanoylperoxide, dioctanoyl peroxide, dilauroyl peroxide, tert-butylperisobutyrate, tert-butyl peracetate, di-tert-amyl peroxide, tert-butylhydroperoxide, azobisisobutyronitrile, 2,2′-azobis(2-amidinopropane)dihydrochloride or 2-2′-azo-bis-(2-methyl-butyronitrile). Mixtures ofthese initiators are suitable as well.

Among the initiators that can be used are reduction/oxidation (i.e.,redox) initiator systems. The redox initiator systems are composed of atleast one, usually inorganic, reducing agent and one organic orinorganic oxidizing agent. The oxidizing component comprises, forexample, the initiators already specified above for the emulsionpolymerization. In the case of the reducing component the compound inquestion comprises, for example, alkali metal salts of sulfurous acid,such as sodium sulfite, sodium hydrogen sulfite, alkali metal salts ofdisulfurous acid such as sodium disulfite, bisulfite addition compoundsof aliphatic aldehydes and ketones, such as acetone bisulfite, orreducing agents such as hydroxymethanesulfinic acid and its salts, orascorbic acid. The redox initiator systems can be used along withsoluble metal compounds whose metallic component is able to occur in aplurality of valence states. Typical redox initiator systems are, forexample, ascorbic acid/iron(II) sulfate/sodium peroxodisulfate,tert-butyl hydroperoxide/sodium disulfite, tert-butyl hydroperoxide/Nahydroxymethanesulfinic acid. The individual components, the reducingcomponent for example, may also be mixutres—for example, a mixture ofsodium salt of hydroxymethanesulfinic acid with sodium disulfite.

The amount of initiators is generally 0.1% to 10% by weight, preferably0.1% to 5% by weight, based on all of the monomers to be polymerized. Itis also possible to use two or more different initiators in the emulsionpolymerization.

The preparation of the polymer dispersion PD) takes place typically inthe presence of at least one surface-active compound. A comprehensivedescription of suitable protective colloids is found in Houben-Weyl,Methoden der organischen Chemie, volume XIV/1, Makromolekulare Stoffe,Georg Thieme Verlag, Stuttgart, 1961, pp. 411 to 420. Suitableemulsifiers are also found in Houben-Weyl, Methoden der organischenChemie, volume 14/1, Makromolekulare Stoffe, Georg Thieme Verlag,Stuttgart, 1961, pages 192 to 208.

Suitable emulsifiers are anionic, cationic, and nonionic emulsifiers. Assurface-active substances it is preferred to use emulsifiers, whoserelative molecular weights are typically below those of protectivecolloids. More particularly it has proven appropriate to use exclusivelyanionic emulsifiers, or a combination of at least one anionic emulsifierand at least one nonionic emulsifier.

Useful nonionic emulsifiers are araliphatic or aliphatic nonionicemulsifiers, examples being ethoxylated mono-, di-, and trialkylphenols(EO degree: 3 to 50, alkyl radical: C₄-C₁₀), ethoxylates of long-chainalcohols (EO degree: 3 to 100, alkyl radical: C₈-C₃₆) and alsopolyethylene oxide/polypropylene oxide homopolymers and copolymers.These may comprise the alkylene oxide units copolymerized in randomdistribution or in the form of blocks. Highly suitable, for example, areEO/PO block copolymers. Preference is given to using ethoxylates oflong-chain alkanols (alkyl radical C₁-C₃₀, average degree ofethoxylation 5 to 100) and, of these, particular preference to thosehaving a linear C₁₂-C₂₀ alkyl radical and an average degree ofethoxylation of 10 to 50, and also ethoxylated monoalkylphenols.

Examples of suitable anionic emulsifiers are alkali metal salts andammonium salts of alkyl sulfates (alkyl radical: C₈-C₂₂), of sulfuricmonoesters with ethoxylated alkanols (EO degree: 2 to 50, alkyl radical:C₁₂-C₁₈) and with ethoxylated alkylphenols (EO degree: 3 to 50, alkylradical: C₄-C₉), of alkylsulfonic acids (alkyl radical: C₁₂-C₁₈), and ofalkylarylsulfonic acids (alkyl radical: C₉-C₁₈). Further suitableemulsifiers are found in Houben-Weyl, Methoden der organischen Chemie,volume XIV/1, Makromolekulare Stoffe, Georg-Thieme-Verlag, Stuttgart,1961, pp. 192-208). Likewise suitable as anionic emulsifiers arebis(phenylsulfonic acid) ethers and/or their alkali metal or ammoniumsalts which carry a C₄-C₂₄ alkyl group on one or both aromatic rings.These compounds are general knowledge, from U.S. Pat. No. 4,269,749, forexample, and are available commercially, in the form for example ofDowfax® 2A1 (Dow Chemical Company).

Suitable cationic emulsifiers are preferably quaternary ammoniumhalides, e.g., trimethylcetylammonium chloride, methyltrioctylammoniumchloride, benzyl-triethylammonium chloride or quaternary compounds ofN—C₆-C₂₀ alkylpyridines, -morpholines or -imidazoles, e.g.,N-laurylpyridinium chloride.

The amount of emulsifier is generally about 0.01% to 10% by weight,preferably 0.1% to 5% by weight, based on the amount of monomers to bepolymerized.

The polymer dispersions PD) may additionally be admixed with typicalauxiliaries and additives. These include, for example, pH modifiers,reductants and bleaches, such as the alkali metal salts ofhydroxymethane sulfinic acid (e.g., Rongalit® C from BASFAktiengesellschaft), complexing agents, deodorants, flavors, odorants,and viscosity modifiers, such as alcohols, e.g., glycerol, methanol,ethanol, tert-butanol, glycol, etc. These auxiliaries and additives maybe added to the polymer dispersions in the initial charge, in one of thefeeds, or after the end of the polymerization.

The polymerization takes place in general at temperatures in a rangefrom 0 to 150° C., preferably 20 to 100° C., more preferably 30 to 95°C. The polymerization takes place preferably under atmospheric pressure,although a polymerization under elevated pressure is also possible, suchas under the autogenous pressure of the components used for thepolymerization. In one suitable version the polymerization takes placein the presence of at least one inert gas, such as nitrogen or argon,for example.

The polymerization medium may be composed either of water alone or ofmixtures of water and water-miscible liquids such as methanol.Preferably just water is used. The emulsion polymerization may becarried out either as a batch operation or in the form of a feedprocess, including staged or gradient procedures. Preference is given tothe feed process, in which a portion of the polymerization batch or elsea polymer seed is introduced as an initial charge and heated to thepolymerization temperature, polymerization is commenced, and then theremainder of the polymerization batch, typically by way of two or morespatially separate feeds, of which one or more comprise the monomers inpure form or an emulsified form, is supplied to the polymerization zonecontinuously, in stages or under the superimposition of a concentrationgradient, with the polymerization being maintained.

The term “seed polymer” is understood by the skilled person to be afinely divided polymer in the form of an aqueous polymer dispersion. Theweight-average particle size of seed polymers (weight average, d₅₀) istypically below 200 nm, frequently in the range from 10 to 150 nm. Themonomer compositions of the seed polymers is generally of minorimportance. Suitability is possessed not only by seed polymers which aresynthesized predominantly from vinylaromatic monomers and moreparticularly from styrene (known as styrene seed), but also by seedpolymers which are synthesized predominantly from C₁-C₁₀ alkyl acrylatesand/or C₁-C₁₀ alkyl methacrylates, such as from a mixture of butylacrylate and methyl methacrylate, for example. Besides these principalmonomers, which typically account for at least 80% by weight and moreparticularly at least 90% by weight of the seed polymer, the seedpolymers may also comprise, in copolymerized form, monomers differentfrom these, especially monomers having an increased solubility in water,examples being monomers having at least one acid function, and/orneutral monomers with an increased solubility in water. The fraction ofmonomers of this kind will generally not exceed 20% by weight and moreparticularly 10% by weight, and, if such monomers are present, thefraction is typically in the range from 0.1% to 10% by weight, based onthe total amount of the constituent monomers of the seed polymer. Themanner in which the initiator is added to the polymerization vessel inthe course of the free-radical aqueous emulsion polymerization is knownto a person of ordinary skill in the art. It can be included in itsentirety in the initial charge to the polymerization vessel, or elseemployed in stages or continuously in accordance with the rate of itsconsumption in the course of the free-radical aqueous emulsionpolymerization. In each case this will depend, in a manner known per seto a person of ordinary skill in the art, both on the chemical nature ofthe initiator system and on the polymerization temperature. Preferably aportion is included in the initial charge and the remainder is suppliedto the polymerization zone in accordance with the rate of itsconsumption.

The dispersions that are formed in the polymerization may be subjected,following the polymerizing operation, to a physical or chemicalaftertreatment. Examples of such techniques are the known techniques forresidual monomer reduction, such as aftertreatment by addition ofpolymerization initiators or mixtures of two or more polymerizationinitiators at suitable temperatures; aftertreatment of the polymersolution by means of water vapor or ammonia vapor; or stripping withinert gas; or treatment of the reaction mixture with oxidizing orreducing reagents; adsorption techniques such as the adsorption ofimpurities on selected media such as activated carbon, for example; oran ultrafiltration, for example.

The aqueous polymer dispersion PD) typically has a solids content of 20%to 70% by weight, preferably 40% to 65% by weight, based on the polymerdispersion including added highly branched polymer. In one specialversion the solids content is at least 50%, more especially at least55%, more especially still at least 58% by weight. Solids contents of atleast 60% by weight or even at least 65% by weight are possible, basedon the aqueous polymer dispersion including added highly branchedpolymer.

The glass transition temperature T_(g) of the emulsion polymer presentin the polymer dispersion is preferably less than 50° C., morepreferably less than 40° C., more particularly less than 30° C.

The resulting aqueous polymer dispersion PD) can be used as it is or asa mixture with further polymers, generally film-forming polymers, as abinder composition in aqueous coating materials, such as paint orvarnish mixtures.

The invention further provides a coating material in the form of anaqueous composition comprising at least one dispersion PD), as definedabove, which comprises a highly branched polymer as an addition. Thehighly branched polymers may be added to the coating material in theform of an additive as well.

Further to the polymer dispersion PD), the binder composition of thecoating material may comprise at least one further film-forming polymer.Included among such are, for example, alkyd resins. Examples of suitablealkyd resins are water-soluble alkyd resins, which preferably have aweight-average molecular weight of 5000 to 40 000. Additionally suitableare alkyd resins having a weight-average molecular weight of more than40 000, specifically of more than 100 000. An alkyd resin is a polyesterwhich has been esterified with drying oil, a fatty acid or the like (U.Poth, Polyester and Alkydharze, Vincentz Network 2005). Suitablewater-soluble alkyd resins are alkyd resins of sufficiently high acidnumber, preferably in the range of 30-65 mg KOH/g. These may ifappropriate be in partly or fully neutralized form. The weight-averagemolecular weight is preferably 8000 to 35 000 and more preferably 10 000to 35 000.

The use of such further film-forming polymers, especially alkyd resins,which raise the VOC content of the coating materials, is not preferred.Preference is therefore given to a coating material that comprises atleast one dispersion PD) and at least one highly branched polymer, butnot film-forming polymer other than the emulsion polymer present in thepolymer dispersion.

The binder compositions of the invention are employed preferably inaqueous coating materials. These coating materials take the form, forexample, of an unpigmented system (clear varnish) or of a pigmentedsystem. The fraction of the pigments can be described by the pigmentvolume concentration (PVC). The PVC describes the ratio of the volume ofpigments (V_(P)) and fillers (V_(F)) to the total volume, composed ofthe volumes of binder (V_(B)), pigments, and fillers of a dried coatingfilm, in percent: PVC=(V_(P)+V_(F))×100/(V_(P)+V_(F)+V_(B)). Coatingmaterials can be divided on the basis of the PVC, for example, asfollows:

highly filled interior paint, wash resistant, white/matt about 85interior paint, scrub resistant, white/matt about 80 semigloss paint,silk-matt about 35 semigloss paint, silk-gloss about 25 high-gloss paintabout 15-25 exterior masonry paint, white about 45-55 clear varnish 0

The invention provides further a coating material in the form of anaqueous composition, comprising:

-   -   at least one dispersion PD) as defined above that comprises a        highly branched polymer as an additive,    -   if appropriate, at least one inorganic filler and/or at least        one inorganic pigment,    -   if appropriate, at least one typical auxiliary, and    -   water.

Preference is given to a coating material comprising:

-   -   10% to 60% by weight, based on the solids content, of at least        one polymer dispersion PD) as defined above,    -   10% to 70% by weight of inorganic fillers and/or inorganic        pigments,    -   0.1% to 20% by weight of typical auxiliaries, and    -   water to 100% by weight.

The fraction of PD) as a proportion of the above coating material isbased on solids, i.e., emulsion polymer and highly branched polymer(s),without water.

The coating materials of the invention, in the form of an aqueouscomposition, are employed preferably as coatings. One embodiment of thepresent invention relates to coating materials in the form of a clearvarnish. Another embodiment of the present invention comprises coatingmaterials in the form of an emulsion paint. The pigmented coatingmaterials of the invention take the form preferably of an aqueoussemigloss or high-gloss paint.

Elucidated in the text below is the composition of a typical emulsionpaint. Emulsion paints comprise generally 30% to 75% and preferably 40%to 65% by weight of nonvolatile constituents. By these are meant allconstituents of the preparation which are not water, but at least thetotal weight of binder, filler, pigment, low-volatility solvents(boiling point above 220° C.), plasticizers for example, and polymericauxiliaries. This figure is accounted for to the extent of about

-   a) 3% to 90%, more particularly 10% to 60%, by weight, by the finely    divided polymer dispersion PD,-   b) 0% to 85%, preferably 5% to 60%, more particularly 10% to 50%, by    weight, by at least one inorganic pigment,-   c) 0% to 85%, more particularly 5% to 60%, by weight, by inorganic    fillers, and-   d) 0.1% to 40%, more particularly 0.5% to 20%, by weight, by typical    auxiliaries.

The polymer dispersions of the invention are suitable more preferablyfor producing high-gloss emulsion paints. These paints are characterizedgenerally by a pigment volume concentration, PVC, in the region of 12%to 30%. But the inventive polymer dispersions also particularly suitmasonry paints with a PVC in the range from 30 to 65 or interior paintswith a PVC in the range from 65 to 80. By the pigment volumeconcentration PVC is meant the ratio, multiplied by 100, of the totalvolume of pigments plus fillers divided by the total volume of pigments,fillers, and binder polymers; cf. Ullmann's Enzyklopädie der technischenChemie, 4th edition, Volume 15, p. 667.

The term “pigment” is used in the context of this inventioncomprehensively to identify all pigments and fillers, examples beingcolor pigments, white pigments, and inorganic fillers. These includeinorganic white pigments such as titanium dioxide, preferably in therutile form, barium sulfate, zinc oxide, zinc sulfide, basic leadcarbonate, antimony trioxide, lithopones (zinc sulfide+barium sulfate),or colored pigments, examples being iron oxides, carbon black, graphite,zinc yellow, zinc green, ultramarine, manganese black, antimony black,manganese violet, Paris blue or Schweinfurt green. Besides the inorganicpigments the emulsion paints of the invention may also comprise organiccolor pigments, examples being sepia, gamboge, Cassel brown, toluidinered, para red, Hansa yellow, indigo, azo dyes, anthraquinonoid andindigoid dyes, and also dioxazine, quinacridone, phthalocyanine,isoindolinone, and metal complex pigments. Also suitable are syntheticwhite pigments with air inclusions to increase the light scattering,such as the Rhopaque® dispersions.

Suitable fillers are, for example, aluminosilicates, such as feldspars,silicates, such as kaolin, talc, mica, magnesite, alkaline earth metalcarbonates, such as calcium carbonate, in the form for example ofcalcite or chalk, magnesium carbonate, dolomite, alkaline earth metalsulfates, such as calcium sulfate, silicon dioxide, etc. Finely dividedfillers are of course preferred in coating materials. The fillers can beused as individual components. In actual practice, however, fillermixtures have proven particularly appropriate, examples being calciumcarbonate/kaolin and calcium carbonate/talc. Glossy coating materialsgenerally include only small amounts of very finely divided fillers, orcomprise no fillers.

Finely divided fillers may also be used to increase the hiding powerand/or to save on the use of white pigments. In order to adjust thehiding power, the hue, and the depth of color, it is preferred to useblends of color pigments and fillers.

The fraction of the pigments can be described, as described above, bythe pigment volume concentration (PVC). Coating materials of theinvention in the form of gloss paints, for example, have a PVC in therange from 12% to 35%, preferably 15% to 30%.

The coating material of the invention (aqueous coating material) maycomprise, in addition to the polymer dispersion PD), at least one highlybranched polymer as an additive, and, if appropriate, additionalfilm-forming polymers and pigment, further auxiliaries.

The typical auxiliaries, in addition to the emulsifiers used in thepolymerization, include wetting agents or dispersants, such as sodium,potassium or ammonium polyphosphates, alkali metal salts and ammoniumsalts of acrylic acid copolymers or maleic anhydride copolymers,polyphosphonates, such as sodium 1-hydroxyethane-1,1-diphosphonate, andsalts of naphthalenesulfonic acids, more particularly their sodiumsalts.

Further suitable auxiliaries are flow control agents, defoamers,biocides, and thickeners. Suitable thickeners are, for example,associative thickeners, such as polyurethane thickeners. The amount ofthe thickener is preferably less than 1% by weight, more preferably lessthan 0.6% by weight, of thickener, based on solids content of thecoating material.

The paints of the invention are produced in a known way by blending thecomponents in mixing apparatus customary for the purpose. It has beenfound appropriate to prepare an aqueous paste or dispersion from thepigments, water, and, if appropriate, the auxiliaries, and only then tomix the polymeric binder, i.e., in general, the aqueous dispersion ofthe polymer, with the pigment paste or pigment dispersion.

The paints of the invention comprise generally 30% to 75% and preferably40% to 65% by weight of nonvolatile constituents. By these are meant allconstituents of the preparation which are not water, but at least thetotal amount of binder, pigment, and auxiliary, based on the solidscontent of the paint. The volatile constituents are primarily water.

Suitable paints are highly glossy paints. The gloss of the paints can bedetermined by DIN 67530. In this case the coating material is appliedwith slot width of 240 μm to a glass plate and is dried at roomtemperature for 72 hours. The test specimen is inserted into acalibrated reflectometer, and a determination is made, with a definedangle of incidence, of the extent to which the light return has beenreflected or scattered. The reflectometer value determined as a measureof the gloss (the higher the value, the higher the gloss).

The gloss of high-gloss paints is preferably greater than 60 at 20° andgreater than 80 at 60°. The reflectometer value is determined at 23° C.and is reported as a dimensionless parameter as a function of theincident angle, e.g., 40 at 20°.

The paint of the invention may be applied to substrates in a typicalway, as for example by spreading, spraying, dipping, rolling, knifecoating, etc.

It is used preferably as an architectural paint, i.e., for coatingbuildings or parts of buildings. The substrates in question may bemineral substrates such as renders, plaster or plasterboard, masonry orconcrete, wood, woodbase materials, metal or paper, wallpaper forexample, or plastic, PVC for example.

The paint is used preferably for internal parts of buildings, such asinterior walls, internal doors, paneling, banisters, furniture, etc.

The paints of the invention feature ease of handling, good processingproperties, and high hiding power. Their pollutant content is low. Theyhave good performance properties, such as high water resistance, goodwet adhesion, not least on alkyd paints, high blocking resistance, goodovercoatability, and good flow on application. The equipment used iseasily cleaned with water.

The invention is elucidated in more detail with reference to thefollowing, nonlimiting examples.

EXAMPLES

I. Synthesis of Highly Branched Polymers

HBP 1: Hyperbranched Polycarbonate

A 4 l flask equipped with stirrer, gas inlet tube, internal thermometer,and reflux condenser was charged with 1417.6 g of diethyl carbonate,2400.0 g of a triol obtained by propoxylating trimethylolpropane with onaverage 1.5 propylene oxide units, and 0.4 g of potassium carbonate andthis initial charge was heated to about 130° C. under atmosphericpressure and under gentle nitrogen gassing. In the course of thepolycondensation there was a reduction in the temperature of thereaction mixture to 105° C. over the course of 4 h, as a result of theethanol formed as condensation product. When the boiling temperatureremained constant, the reflux condenser was replaced by a distillationapparatus consisting of a 20 cm packed column, a descending condenser,and a receiver, and the ethanol was distilled off continuously. When 770g of distillate had been removed, the reaction mixture was cooled to100° C. and the potassium carbonate was neutralized by addition of 0.5 gof 85% strength phosphoric acid. The mixture was stirred at 100° C. for1 h more. This was followed by stripping with nitrogen at 140° C. forabout 0.5 h, during which remaining residues of volatile components wereremoved. Thereafter the product was cooled and analyzed. The OH numberwas 421 mg KOH/g; the molecular weight determined by GPC (eluent=DMAC,calibration=PMMA) were M_(n)=980 g/mol and M_(w)=1450 g/mol.

HBP 2: Hyperbranched Polycarbonate

A 4 l flask equipped with stirrer, gas inlet tube, internal thermometer,and reflux condenser was charged with 591 g of diethyl carbonate, 3350 gof a triol obtained by ethoxylating trimethylolpropane with on average12 ethylene oxide units, and 0.5 g of potassium hydroxide and thisinitial charge was heated to about 140° C. under atmospheric pressureand under gentle nitrogen gassing. In the course of the polycondensationthere was a reduction in the temperature of the reaction mixture to 110°C. over the course of 4 h, as a result of the ethanol formed ascondensation product. When the boiling temperature remained constant,the reflux condenser was replaced by a distillation apparatus consistingof a 20 cm packed column, a descending condenser, and a receiver, andthe ethanol was distilled off continuously. When 405 g of distillate hadbeen removed, the reaction mixture was cooled to 100° C. and thepotassium hydroxide was neutralized by addition of 0.5 g of 85% strengthphosphoric acid. The mixture was stirred at 100° C. for 1 h more. Thiswas followed by stripping with nitrogen at 140° C. for about 0.5 h,during which remaining residues of volatile components were removed.Thereafter the product was cooled and analyzed. The OH number was 151 mgKOH/g; the molecular weight determined by GPC (eluent=DMAC,calibration=PMMA) were M_(n)=2750 g/mol and M_(w)=5700 g/mol.

HBP 3: Hyperbranched Polycarbonate

A 4 l flask equipped with stirrer, gas inlet tube, internal thermometer,and reflux condenser was charged with 1182 g of diethyl carbonate, 2750g of a triol obtained by ethoxylating trimethylolpropane with on average3 ethylene oxide units, and 0.4 g of potassium carbonate and thisinitial charge was heated to about 140° C. under atmospheric pressureand under gentle nitrogen gassing. In the course of the polycondensationthere was a reduction in the temperature of the reaction mixture to 110°C. over the course of 4 h, as a result of the ethanol formed ascondensation product. When the boiling temperature remained constant,the reflux condenser was replaced by a distillation apparatus consistingof a 20 cm packed column, a descending condenser, and a receiver, andthe ethanol was distilled off continuously. When 828 g of distillate hadbeen removed, the reaction mixture was cooled to 100° C. and thepotassium carbonate was neutralized by addition of 0.5 g of 85% strengthphosphoric acid. The mixture was stirred at 100° C. for 1 h more. Thiswas followed by stripping with nitrogen at 140° C. for about 0.5 h,during which remaining residues of volatile components were removed.Thereafter the product was cooled and analyzed. The OH number was 274 mgKOH/g; the molecular weight determined by GPC (eluent=DMAC,calibration=PMMA) were M_(n)=2170 g/mol and M_(w)=5400 g/mol.

II. Preparation of Polymer Dispersions Example 1 Preparation ofDispersion 1

A polymerization vessel equipped with metering apparatus and temperatureregulation was charged with the following:

Initial Charge:

528.0 g  water 46.7 g a polystyrene seed dispersion having a solidscontent of 33% and average particle size of 30 nm 3.67 g a 15% strengthaqueous solution of sodium lauryl sulfate

Thereafter this initial charge was heated to 85° C. with stirring.Subsequently, with this temperature maintained, 5% by weight of feed 2was added and the mixture was stirred for 5 minutes. Thereafter feed 1was metered in over 180 minutes, and the remainder of feed 2 in parallelover 195 minutes.

Feed 1:

543.2 g water 125.4 g a 15% strength aqueous solution of sodium laurylsulfate 458.0 g n-butyl acrylate 399.6 g methyl methacrylate 165.1 gstyrene 22.78 g methacrylic acid 21.45 g ureidomethacrylate(N-(2-methacryloyloxyethyl)imidazolidin-2-one)  33.0 g Bisomer MPEG 350MA (methoxypolyethylene glycol monomethacrylate from Laporte PerformanceChemicals UK)Feed 2:

83.6 g water  4.4 g sodium peroxodisulfate

After the end of feed 1, 22 g of water were added; after the end of feed2, polymerization was continued for 30 minutes and the batch wasneutralized with 7.47 g of ammonia (25% strength aqueous solution).Thereafter 13.2 g of hydrogen peroxide (5% strength aqueous solution)were added and a solution of 0.557 g of ascorbic acid in 4.96 g of waterwas metered in over 60 minutes. Thereafter the dispersion was allowed tocool and was filtered through a 125 μm filter. This gave 2.48 kg of a46% dispersion.

The hyperbranched polymers HBP 1 and HBP 2 were admixed to dispersion 1as pure substances, in amounts as indicated in Tables 3 and 4.

Example 2 Preparation of Dispersion 2

A polymerization vessel equipped with metering apparatus and temperatureregulation was charged with the following:

Initial Charge:

584.0 g  water 56.9 g a polystyrene seed dispersion having a solidscontent of 33% and an average particle size of 30 nm 4.47 g a 15%strength aqueous solution of sodium lauryl sulfate

Thereafter this initial charge was heated to 85° C. with stirring.Subsequently, with this temperature maintained, 5% by weight of feed 2was added and the mixture was stirred for 5 minutes. Thereafter feed 1was metered in over 180 minutes, and the remainder of feed 2 in parallelover 195 minutes.

Feed 1:

595.6 g water 153.0 g a 15% strength aqueous solution of sodium laurylsulfate 576.3 g n-butyl acrylate 529.6 g methyl methacrylate 207.6 gstyrene 28.59 g methacrylic acid

Feed 2:

16.1 g a 5% strength aqueous solution of sodium peroxodisulfate

After the end of feed 1, 27 g of water were added; after the end of feed2, polymerization was continued for 30 minutes and the batch wasneutralized with 9.13 g of ammonia (25% strength aqueous solution).Thereafter 16.11 g of hydrogen peroxide (5% strength aqueous solution)were added and 6.71 g of a 10% strength aqueous solution of ascorbicacid were metered in over 60 minutes. Thereafter the dispersion wasallowed to cool and was filtered through a 125 μm filter. This gave 2.85kg of a 48% dispersion.

The hyperbranched polymer HBP 3 was admixed to dispersion 2 as puresubstances, in amounts as indicated in Table 5.

III. Performance Examples 1. Preparation of Aqueous Paints

The individual components (for manufacturer see Table 1) were metered inthe amount (parts by weight) and sequence as indicated in Table 2 withstirring using a toothed disk stirrer. After the titanium dioxidepigment had been added the speed was increased to 2000 rpm and the batchwas dispersed until the pigment paste was smooth, i.e., free of lumps.Then, if necessary, it was cooled to room temperature and the remainingcomponents were added at reduced speed. The binder of the formulationindicated in Table 2 for an aqueous coating material comprised no highlybranched or hyperbranched polymer. For the inventive coating materialswith hyperbranched polymers, the corresponding weight fraction of bindergoes up, compensated by a corresponding reduction in the fraction ofwater.

TABLE 1 Function Name Manufacturer Dispersant Disperbyk ® 190 Byk-ChemieGmbH, Wesel (high molecular mass block copolymer with pigment-activegroups) Defoamers Byk ® 020 Byk-Chemie GmbH, Wesel (polysiloxane) TegoAirex ® 902W Tego Chemie, Essen (silica-containing poly(ether-siloxane)copolymer Titanium dioxide Kronos ® 2190 Kronos Titan GmbH, pigmentLeverkusen Thickeners DSX 2000 and DSX Cognis Deutschland GmbH & 1514(polyurethane- Co. KG, Düsseldorf based associative thickeners)

TABLE 2 Formulation of the aqueous coating materials Component NameAmount [g] Water 10.72 Defoamer Byk ® 020 0.96 Dispersant Disperbyk ®190 4.7 Thickeners DSX 2000/1514 (1:0.3) 2.46 Titanium dioxide Kronos ®2190 47.16 pigment Paste 66 Water 7.7 Solvent Propylene glycol 4.36Defoamer Tego Airex ® 902W 0.04 Binder 121.9 Total 200.092. Testing of aqueous paints (coating materials)

The gloss of the coating material was determined in accordance with DINEN ISO 2813: the coating material is applied with a slot width of 240 μmto a glass plate and dried at room temperature for 72 hours. The testspecimen is inserted into a calibrated haze-gloss reflectometer(Byk-Gardner, Geretsried) and the reflectometer value at 20° and 60°incident angle, and also the haze, are read off. The reflectometer valuedetermined is a measure of the gloss (the higher the value, the higherthe gloss).

TABLE 3 Addition of hyperbranched polymer HBP 1 to acrylate dispersion1: Acrylate dispersion 1 blended with different amounts of HBP 1Fraction* 0% 1% 2.5% 5% Gloss (60°) 77.5 78.8 84 89.4 Gloss (20°) 52.260.7 66.9 78.2 Haze 187 129 105 25.5 *Weight percent based on dispersionsolids

TABLE 4 Addition of hyperbranched polymer HBP 2 to acrylate dispersion1: Acrylate dispersion 1 blended with different amounts of HBP 2Fraction* 0% 1% 2.5% 5% Gloss (60°) 77.5 80.5 84.4 85.1 Gloss (20°) 52.259.7 66.3 71.9 Haze 187 126 99.3 34.2 *Weight percent based ondispersion solids

As the fraction of hyperbranched polymer goes up there is a rise in thegloss and a fall in the haze.

TABLE 5 Addition of hyperbranched polymer HBP 3 to acrylate dispersion 2Acrylate dispersion 2 blended with HBP 3 Fraction* in % by weight, basedon dispersion solids 0% 5% Gloss (20°) 41 67 Gloss (60°) 79 88 Haze 11370

1. A method of producing a coating with increased gloss comprisingapplying to a substrate an aqueous coating material which comprises anaqueous polymer dispersion and a highly branched polymer; wherein thehighly branched polymer is at least one hyperbranched polymer which hasa degree of branching of 10% to 95%.
 2. The method according to claim 1,wherein the highly branched polymer is at least one selected from thegroup consisting of polycarbonates, polyesters, polyethers,polyurethanes, polyureas, polyamines, polyamides, poly(ureaurethanes),poly(etheramines), poly(esteramines), poly(etheramides),poly(esteramides), poly(amidoamines), poly(estercarbonates),poly(ethercarbonates), poly(etheresters), poly(etherestercarbonates),and mixtures thereof.
 3. The method according to claim 1, wherein thehighly branched polymer is a hyperbranched polycarbonate,poly(ethercarbonate), poly(estercarbonate) or poly(etherestercarbonate)or a mixture of hyperbranched polymers which comprises at least onehyperbranched polycarbonate, poly(ethercarbonate), poly(estercarbonate)or poly(etherestercarbonate).
 4. The method according to claim 1,wherein the highly branched polymer is a hyperbranched polyester of A₂B₃type.
 5. The method according to claim 1, wherein the aqueous polymerdispersion comprises 0.1% to 15% by weight, based on the total weight ofthe polymer dispersion, of at least one highly branched polymer.
 6. Themethod according to claim 1, wherein the aqueous polymer dispersion isobtained by free-radical emulsion polymerization of at least oneethylenically unsaturated monomer.
 7. The method according to claim 6,wherein the monomer is selected from the group consisting of esters ofα,β-ethylenically unsaturated monocarboxylic and dicarboxylic acids withC₁-C₂₀ alkanols, vinylaromatics, esters of vinyl alcohol with C₁-C₃₀monocarboxylic acids, ethylenically unsaturated nitriles, vinyl halides,vinylidene halides, monoethylenically unsaturated carboxylic andsulfonic acids, phosphorus monomers, esters of α,β-ethylenicallyunsaturated monocarboxylic and dicarboxylic acids with C₂-C₃₀alkanediols, amides of α,β-ethylenically unsaturated monocarboxylic anddicarboxylic acids with C₂-C₃₀ amino alcohols which contain a primary orsecondary amino group, primary amides of α,β-ethylenically unsaturatedmonocarboxylic acids and their N-alkyl and N,N-dialkyl derivatives,N-vinyllactams, open-chain N-vinylamide compounds, esters of allylalcohol with C₁-C₃₀ monocarboxylic acids, esters of α,β-ethylenicallyunsaturated monocarboxylic and dicarboxylic acids with amino alcohols,amides of α,β-ethylenically unsaturated monocarboxylic and dicarboxylicacids with diamines which contain at least one primary or secondaryamino group, N,N-diallylamines, N,N-diallyl-N-alkylamines, vinyl- andallyl-substituted nitrogen heterocycles, vinyl ethers,C₂-C₈-monoolefins, nonaromatic hydrocarbons having at least twoconjugated double bonds, polyether (meth)acrylates, monomers containingurea groups, and mixtures thereof
 8. The method according to claim 6,wherein the free-radical emulsion polymerization is carried out using atleast 40% by weight, based on the total weight of the monomers, of atleast a first monomer selected from the group consisting of esters ofα,β-ethylenically unsaturated monocarboxylic and dicarboxylic acids withC₁-C₂₀ alkanols, vinylaromatics, esters of vinyl alcohol with C₁-C₃₀monocarboxylic acids, ethylenically unsaturated nitriles, vinyl halides,vinylidene halides, and mixtures thereof
 9. The method according toclaim 8, wherein the free-radical emulsion polymerization is carried outadditionally using up to 60% by weight, based on the total weight of themonomers, of at least a second monomer selected from the groupconsisting of ethylenically unsaturated monocarboxylic and dicarboxylicacids and the anhydrides and monoesters of ethylenically unsaturateddicarboxylic acids, (meth)acrylamides, C₁-C₁₀ hydroxyalkyl(meth)acrylates, C₁-C₁₀ hydroxyalkyl(meth)acrylamides, and mixturesthereof.
 10. The method according to claim 8, wherein the free-radicalemulsion polymerization is carried out additionally using up to 25% byweight, based on the total weight of the monomers, of at least onepolyether (meth)acrylate.
 11. The method according to claim 10, whereinthe polyether (meth)acrylate is represented by formulae I or II ormixtures thereof

in which n is an integer from 3 to 15; R^(a) is hydrogen, C₁-C₂₀ alkyl,C₅-C₈ cycloalkyl or C₆-C₁₄ aryl; and R^(b) is hydrogen or methyl. 12.The method according to claim 8, wherein the free-radical emulsionpolymerization is carried out additionally using up to 25% by weight,based on the total weight of the monomers, of at least one monomercontaining urea groups.
 13. A coating material in the form of an aqueouscomposition comprising: at least one aqueous polymer dispersion asdefined in claim 1, comprising a highly branched polymer as an additive;optionally at least one inorganic filler and/or at least one inorganicpigment; optionally at least one auxiliary; and water.
 14. A transparentvarnish comprising the coating material according to claim
 13. 15. Anemulsion paint comprising the coating material according to claim 13.16. The emulsion paint according to claim 15, comprising: 10% to 60% byweight of at least one aqueous polymer dispersion which comprises ahighly branched polymer as an additive; 10% to 70% by weight ofinorganic fillers and/or inorganic pigments; 0.1% to 20% by weight ofauxiliaries; and water to 100% by weight.
 17. An aqueous semigloss orhigh-gloss paint comprising the emulsion paint according to claim 15.18. A high-gloss paint comprising the emulsion paint according to claim15 having a gloss of greater than 60 at 20° incident angle.
 19. Ahigh-gloss paint comprising the emulsion paint according to claim 15having a gloss of greater than 80 at 60° incident angle.
 20. Ahigh-gloss paint comprising the emulsion paint according to claim 15having a pigment volume concentration in the range from 12 to 35%. 21.The method according to claim 1, wherein the aqueous polymer dispersioncomprises 0.5% to 10% by weight, based on the total weight of thepolymer dispersion, of the highly branched polymer.
 22. The methodaccording to claim 1, wherein the aqueous polymer dispersion comprises1% to 5% by weight, based on the total weight of the polymer dispersion,of the highly branched polymer.